Journal of Community Engagement Research for Sustainability
Di era Revolusi Industri 4.0, sistem pembelajaran yang masih menggunakan kertas (paper-based) ata... more Di era Revolusi Industri 4.0, sistem pembelajaran yang masih menggunakan kertas (paper-based) ataupun pembelajaran tatap muka (face to face) harus dapat diubah menjadi kegiatan pembelajaran yang berbasis teknologi informasi dan komunikasi (TIK). Seorang guru harus dapat memanfaatkan TIK sebagai alat bantu proses pembelajaran agar lebih menarik, efektif dan efisien. Tujuan kegiatan ini adalah untuk memberikan bimbingan teknis bagi guru-guru Sekolah Dasar Gugus Kaktus Bangkinang - Kabupaten Kampar dalam bentuk pengenalan konsep TIK di sekolah, penggunaan aplikasi pembelajaran interaktif, dan merancang skenario pembelajaran aktif melalui pembelajaran daring (online) sesuai mata pelajaran yang diampu. Kegiatan Pelatihan Merancang Pembelajaran Aktif Berbasis Online dilaksanakan di Kabupaten Kampar. Guru-guru yang tergabung dalam Gugus Kaktus terdiri dari guru-guru yang bersal dari 6 sekolah Dasar. Tahapan pelaksanaan diawali dengan pretest, yang bertujuan untuk mengetahui pengetahuan awa...
Abstract The successful integration of nanotechnology as a platform for food sensors offers treme... more Abstract The successful integration of nanotechnology as a platform for food sensors offers tremendous benefits in detecting contaminants, particularly in their applications for food quality and safety. The sensors based on nanomaterials (nanosensor), both chemical sensors (chemical nanosensors) and biosensors (nanobiosensors), can be used online and integrated into existing manufacturing process and distribution line or off-line as rapid, simple, and portable, as well as disposable, sensors for food contaminants. Food contaminants could be residues of pesticides, veterinary and human drugs, microbial toxins, preservatives, contaminants from food processing and packaging, and other residues. This milieu of compounds can pose difficulties in the detection of food contaminants. Nanosensors with their novel uses are the emerging method that could be used for the detection of many food contaminants, even mycotoxins and many food allergens. Whether it used as online or off-line, the nanosensor can be integrated with wireless technology and used for real-time transmission of contaminant alarm or test results to remote servers, providing rapid screening and reporting. Thus nanosensors are more cost-effective, rapid, and more sensitive than instrumental and conventional procedures. Recent developments in nanosensors may provide more applications for their use in food contaminant detection. The future role of these nanosensors will become even more important as the food laboratory is faced with the increasing pressure to reduce cost, time, and complexity. The objective of this chapter is to give a general overview of the possible application of nanosensors in the food contaminant detection and analysis.
Bakteri ureolitik adalah bakteri yang memiliki aktivitas enzim urease yang menghidrolisis urea un... more Bakteri ureolitik adalah bakteri yang memiliki aktivitas enzim urease yang menghidrolisis urea untuk menghasilkan karbondioksida dan amonia. Bakteri ini dapat diaplikasikan untuk agrikultur, kesehatan dan konstruksi. Penelitian ini bertujuan untuk melihat aktivitas urease Bacillus SP 34 dan Bacillus SP 83 dan kemampuannya menghasilkan kalsium karbonat. Pengujian aktivitas urease secara kuantitatif dilakukan dalam Nutrient Broth selama 18 jam. Produksi kalsit menggunakan medium NB-U/Ca inkubasi selama 7 hari. Hasil penelitian diketahui Bacillus SP 34 aktivitas urease yaitu 0,058 U/ml dan kalsium karbonat terbentuk 169.0 mg dan Bacillus SP 83 dengan aktivitas urease 0.065 U/ml dan kalsium karbonat terbentuk 105.0 g. Ke dua isolat ini dapat dikembangkan untuk bidang pertanian dan konstruksi sebagai bahan campuran beton.
A fluorescence-based fiber optic toxicity biosensor based on genetically modified Escherichia col... more A fluorescence-based fiber optic toxicity biosensor based on genetically modified Escherichia coli (E. coli) with green fluorescent protein (GFP) was developed for the evaluation of the toxicity of several hazardous heavy metal ions. The toxic metals include Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(III). The optimum fluorescence excitation and emission wavelengths of the optical biosensor were 400 ± 2 nm and 485 ± 2 nm, respectively. Based on the toxicity observed under optimal conditions, the detection limits of Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(III) that can be detected using the toxicity biosensor were at 0.04, 0.32, 0.46, 2.80, 100, 250, 400, 720 and 2600 μg/L, respectively. The repeatability and reproducibility of the proposed biosensor were 3.5%-4.8% RSD (relative standard deviation) and 3.6%-5.1% RSD (n = 8), respectively. The biosensor response was stable for at least five weeks, and demonstrated higher sensitivity towards metal toxicity evaluation when compared to a conventional Microtox assay.
In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxici... more In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri) encapsulated in alginate microspheres is described. Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(II) were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor. The loss of bioluminescence response from immobilized A. fischeri bacterial cells corresponds to changes in the toxicity levels. The inhibition of the luminescent biosensor response collected at excitation and emission wavelengths of 287 ± 2 nm and 487 ± 2 nm, respectively, was found to be reproducible and repeatable within the relative standard deviation (RSD) range of 2.4-5.7% (n = 8). The toxicity biosensor based on alginate micropsheres exhibited a lower limit of detection (LOD) for Cu(II) (6.40 μg/L), Cd(II) (1.56 μg/L), Pb(II) (47 μg/L), Ag(I) (18 μg/L) than Zn(II) (320 μg/L), Cr(VI) (1,000 μg/L), Co(II) (1700 μg/L), Ni(II) (2800 μg/L), and Fe(III) (3100 μg/L). Such LOD values are lower when compared with other previous reported whole cell toxicity biosensors using agar gel, agarose gel and cellulose membrane biomatrices used for the immobilization of bacterial cells. The
The basic concept of environmental toxicity and its importance in the evaluation of ecosystem hea... more The basic concept of environmental toxicity and its importance in the evaluation of ecosystem health will be introduced. Toxicity evaluation theory and practice will be briefly discussed. Traditional techniques such as bioassays for environmental toxicity evaluation will be introduced where the advantages and disadvantages will be presented. But the main focus of environmental toxicity evaluation will be on the use of more recent techniques for rapid environmental toxicity assessments such as toxicity biosensor and its basic concept, current applications, and future prospects.
Journal of Information Technology Education-Research, 2021
Aim/Purpose The purposes of this research are to analyze online learning management activities co... more Aim/Purpose The purposes of this research are to analyze online learning management activities conducted by the principals of junior high schools in Indonesia in facing COVID-19 as well as to discuss their perspective and expectations towards online learning activities when facing COVID-19 and after COVID-19 has passed. Background Due to the rapid spread of the COVID-19 pandemic, the Indonesian Minister of Education and Culture instructed that teaching and learning activities for all levels of education in Indonesia must be carried out online from home. There have been comprehensive reports about the various forms of online learning, its effects on students, the challenges, the learning transition from offline to online, and teachers' views on this new approach. Very few, if any, focus on how principals act upon the transition during this COVID-19 pandemic. Therefore, this research focuses on how principals overcome various problems that arise in the implementation of online lea...
This study aims to analyze Distance Learning (PJJ) online science teacher candidate students in P... more This study aims to analyze Distance Learning (PJJ) online science teacher candidate students in Pekanbaru City during the COVID-19 Pandemic. This research is a survey research with the type of public opinion survey. Sampling was taken through purposive sampling method. The data collected is ordinal data via e-questionnaire (Google form), through a summative response scale using a modified Likert scale with 4 answer choices. The results showed that the form of learning during the pandemic using various dominant applications were Google Meet (22.47%), Google Classroom (17.95%), WhatsApp (15.56%), and Schoology (11.70%). Online PJJ is not effectively carried out based on the availability of infrastructure, convenience and accessibility, difficulty in lecture materials, time, increased competence, and variety of courses. The implementation of PJJ is in accordance with the learning objectives because lecturers vary the use of applications, interactions run smoothly, and lecturers motivat...
Since the corona virus disease (Covid-19) was found in patients in Wuhan, China and this virus ha... more Since the corona virus disease (Covid-19) was found in patients in Wuhan, China and this virus has shown rapid transmission and has become a worldwide epidemic. As a result, online learning is applied to all universities in Indonesia by using various applications. This work is aimed for analyzing the implementation of online learning during the Covid -19 pandemic and is directed for investigating the form, implementation and expectations of students in online learning. This research was involved 231 samples consisting of all chemistry education student at Universities in Riau. The data directly collected through e-questionnaire using google form. The data obtained from the questionnaire were analyzed quantitatively and the interview data in the form of short questions were analyzed qualitatively. All the obtained data were carfully described in descriptive form. Basid oh the analysis, it was found that the type of online learning was dominated by using google classroom and zoom meet...
This study aims to produce an online learning evaluation instrument that is considered feasible b... more This study aims to produce an online learning evaluation instrument that is considered feasible by material experts, evaluation experts and through item analysis and user response questionnaires. This research was conducted with a 4D development model. The instruments used in this study were the material expert's feasibility assessment sheet, evaluation expert, item analysis and user response questionnaires, namely lecturers and students. The data analysis in this study used a rating scale and the item analysis used the product-moment, Kuder-Richardson, the discrimination power and the difficulty level of the questions. Through the item analysis of the 25 questions selected 10 questions that meet the discrimination power,difficulty level, validation and reliability. The reliability coefficient is 0.851 which is classified as high reliability. Meanwhile, the evaluation of material experts was 85.4%, expert evaluation was 88%, student response was 90.7% and lecturers were 90%. Bas...
The research aims to determine the effect of learning style on students’ performance through onli... more The research aims to determine the effect of learning style on students’ performance through online learning during the Covid-19 pandemic. The subjects of study are 269 chemistry education students at three universities in Indonesia. The data collection of learning style uses a Likert scale questionnaire, and learning performance is obtained from students’ grade point average. In this research, students’ learning style was divided into visual, auditorial, and kinesthetic. Data were analyzed using descriptive statistics with linear regression and ANOVA tests. The learning styles positively affect student learning performance by 4.7%, while 95.3% of other factors are not examined in this study. The learning performance of students with auditory is higher than visual and kinesthetic learning styles. Based on the inferential analysis, there is no significant difference in student learning performance based on student learning styles. Therefore, students with different learning styles ha...
Proceedings of the 1st International Conference on Education, Humanities, Health and Agriculture, ICEHHA 2021, 3-4 June 2021, Ruteng, Flores, Indonesia
This study aims to describe and analyze about: forms of e-learning-based distance learning activi... more This study aims to describe and analyze about: forms of e-learning-based distance learning activities carried out at the Department of Social Studies FKIP Riau. This type of research is descriptive qualitative research. The data to be collected is ordinal data, which comes from the results of e-questionnaires(google form). The data collected is summative response scale,using a modified Likert scale with 3 answer options. Student responses are organized based on 3 levels of Likert Scale: 1 = Yes; 2 = No; 3 = Hesitation. The data obtained is then analyzed through a descriptive statistical analysis of percentages. The results showed that the form of implementation of distance learning activities carried out in the department of Social Sciences FKIP Riau University refers to the indicators of distance learning, namely: clear learning objectives, relevant to the needs, quality of education, efficient and effectiveness of the program, equality and expansion of learning opportunities, inde...
Peran mikroba endofit dalam memproduksi metabolit sekunder dengan kualitas yang hampir sama denga... more Peran mikroba endofit dalam memproduksi metabolit sekunder dengan kualitas yang hampir sama dengan tanaman aslinya sangat potensial untuk dikembangkan. Penelitian ini bertujuan untuk menyelidiki bakteri endofit yang terdapat didalam jaringan kulit batang Laban (Vitex pubescens Vahl) serta kemampuannya untuk memproduksi metabolit bioaktif yang mempunyai aktivitas sitotoksik. Dalam penelitian ini digunakan teknik inokulasi langsung dengan jalan meletakkan sampel tanaman di atas permukaan Nutrient Agar (NA). Metoda Micro tetrazolium (MTT) digunakan untuk menetapkan aktivitas sitotoksik dari ekstrak etilasetat. Bakteri endofit yang berhasil diisolasi sebanyak 3 isolat yaitu Bakteri-2A, Bakteri -3B dan Bakteri-6C. Berdasarkan hasil penapisan dari 3 isolat tersebut didapatkan dua bakteri yang memiliki aktivitas potensial yang baik terhadap sel serviks (HeLa) yaitu isolat Bakteri – 6C (IC50 = 82.54 µg/mL) dan Bakteri-2A (IC50 = 297.09 µg/mL). Isolat yang menunjukkan aktivitas sitotoksik t...
Rapid determination of toxicity based on changes in the bioluminescent signal of marine bacterium... more Rapid determination of toxicity based on changes in the bioluminescent signal of marine bacterium Aliivibrio fischeri (A. fischeri) to evaluate toxicity of Ag(I) has been successfully developed. Assessment of toxicity was designed using inhibition of bioluminescent signal from A. fischeri bacteria, which was exposed with toxic material of Ag(I). This metal ion was utilized as a model of toxic material to evaluate the effects of cytotoxicity on bacteria cell. Measurement of bioluminescent were taken based on differences in bacterial cell signals before and after exposure to Ag(I) ion at an emission wavelength of 488±2 nm. The concentration of bacterial cell was used to assess the toxicity of Ag(I) at optical density (OD600 nm) of 0.78 Abs. The results found that the linear response of Ag toxicity was in the range of 0.05–10 mg/L, with EC50% of 8.42 mg/L for 4 minutes. The repeatability value within the relative standard deviation (RSD) was 2.5-4.7% (n=8). The results demonstrated th...
This article details an investigation on the mechanism of corrosion inhibition of mild steel usin... more This article details an investigation on the mechanism of corrosion inhibition of mild steel using amylose-acetate-blended carboxymethyl chitosan (AA-CMCh) in acidic media in the context of kinetic and thermodynamic parameters. The surface of mild steel was exposed to test solutions and evaluated using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The activation energy (Ea), free energy of adsorption (ΔG), enthalpy of activation (ΔHads), and entropy of activation (ΔSads) were determined in order to elucidate the mechanism of corrosion inhibition. The results confirmed that AA could be improved using CMCh as a corrosion inhibitor. The corrosion rate decreased from 1109.00 to 229.70 mdd (79.29%), while corrosion inhibition increased from 35.13 to 89.72%. Sulfate acid (H2SO4) of 0.25 M also helped in decreasing the corrosion rate from 2664.4 to 1041.67 mdd (60.9%) while also in increasing corrosion inhibition from 56.94 to 68.31%. The calculated val...
A tri-enzyme system consisting of choline kinase/choline oxidase/horseradish peroxidase was used ... more A tri-enzyme system consisting of choline kinase/choline oxidase/horseradish peroxidase was used in the rapid and specific determination of the biomarker for bacterial sepsis infection, secretory phospholipase Group 2-IIA (sPLA2-IIA). These enzymes were individually immobilized onto the acrylic microspheres via succinimide groups for the preparation of an electrochemical biosensor. The reaction of sPLA2-IIA with its substrate initiated a cascading enzymatic reaction in the tri-enzyme system that led to the final production of hydrogen peroxide, which presence was indicated by the redox characteristics of potassium ferricyanide, K₃Fe(CN)₆. An amperometric biosensor based on enzyme conjugated acrylic microspheres and gold nanoparticles composite coated onto a carbon-paste screen printed electrode (SPE) was fabricated and the current measurement was performed at a low potential of 0.20 V. This enzymatic biosensor gave a linear range 0.01-100 ng/mL (² = 0.98304) with a detection limit r...
An ultrasensitive electrochemical biosensor for the determination of pathogenic Vibrio cholerae (... more An ultrasensitive electrochemical biosensor for the determination of pathogenic Vibrio cholerae (V. cholerae) DNA was developed based on polystyrene-co-acrylic acid (PSA) latex nanospheres-gold nanoparticles composite (PSA-AuNPs) DNA carrier matrix. Differential pulse voltammetry (DPV) using an electroactive anthraquninone oligonucleotide label was used for measuring the biosensor response. Loading of gold nanoparticles (AuNPs) on the DNA-latex particle electrode has significantly amplified the faradaic current of DNA hybridisation. Together with the use of a reported probe, the biosensor has demonstrated high sensitivity. The DNA biosensor yielded a reproducible and wide linear response range to target DNA from 1.0 × 10 −21 to 1.0 × 10 −8 M (relative standard deviation, RSD = 4.5%, n = 5) with a limit of detection (LOD) of 1.0 × 10 −21 M (R 2 = 0.99). The biosensor obtained satisfactory recovery values between 91 and 109% (n = 3) for the detection of V. cholerae DNA in spiked samples and could be reused for six consecutive DNA assays with a repeatability RSD value of 5% (n = 5). The electrochemical biosensor response was stable and maintainable at 95% of its original response up to 58 days of storage period.
The present research describes a simple method for the identification of the gender of arowana fi... more The present research describes a simple method for the identification of the gender of arowana fish (Scleropages formosus). The DNA biosensor was able to detect specific DNA sequence at extremely low level down to atto M regimes. An electrochemical DNA biosensor based on acrylic microsphere-gold nanoparticle (AcMP-AuNP) hybrid composite was fabricated. Hydrophobic poly(n-butylacrylate-N-acryloxysuccinimide) microspheres were synthesised with a facile and well-established one-step photopolymerization procedure and physically adsorbed on the AuNPs at the surface of a carbon screen printed electrode (SPE). The DNA biosensor was constructed simply by grafting an aminated DNA probe on the succinimide functionalised AcMPs via a strong covalent attachment. DNA hybridisation response was determined by differential pulse voltammetry (DPV) technique using anthraquinone monosulphonic acid redox probe as an electroactive oligonucleotide label (Table ). A low detection limit at 1.0 × 10 -18 M with a wide linear calibration range of 1.0 × 10 -18 to 1.0 × 10 -8 M (R 2 = 0.99) can be achieved by the proposed DNA biosensor under optimal conditions. Electrochemical detection of arowana DNA can be completed within 1 hour. Due to its small size and light weight, the developed DNA biosensor holds high promise for the development of functional kit for fish culture usage.
Molecularly imprinted (MIP) polymeric microspheres are generally a more stable material for hormo... more Molecularly imprinted (MIP) polymeric microspheres are generally a more stable material for hormone sensing application.
Journal of Community Engagement Research for Sustainability
Di era Revolusi Industri 4.0, sistem pembelajaran yang masih menggunakan kertas (paper-based) ata... more Di era Revolusi Industri 4.0, sistem pembelajaran yang masih menggunakan kertas (paper-based) ataupun pembelajaran tatap muka (face to face) harus dapat diubah menjadi kegiatan pembelajaran yang berbasis teknologi informasi dan komunikasi (TIK). Seorang guru harus dapat memanfaatkan TIK sebagai alat bantu proses pembelajaran agar lebih menarik, efektif dan efisien. Tujuan kegiatan ini adalah untuk memberikan bimbingan teknis bagi guru-guru Sekolah Dasar Gugus Kaktus Bangkinang - Kabupaten Kampar dalam bentuk pengenalan konsep TIK di sekolah, penggunaan aplikasi pembelajaran interaktif, dan merancang skenario pembelajaran aktif melalui pembelajaran daring (online) sesuai mata pelajaran yang diampu. Kegiatan Pelatihan Merancang Pembelajaran Aktif Berbasis Online dilaksanakan di Kabupaten Kampar. Guru-guru yang tergabung dalam Gugus Kaktus terdiri dari guru-guru yang bersal dari 6 sekolah Dasar. Tahapan pelaksanaan diawali dengan pretest, yang bertujuan untuk mengetahui pengetahuan awa...
Abstract The successful integration of nanotechnology as a platform for food sensors offers treme... more Abstract The successful integration of nanotechnology as a platform for food sensors offers tremendous benefits in detecting contaminants, particularly in their applications for food quality and safety. The sensors based on nanomaterials (nanosensor), both chemical sensors (chemical nanosensors) and biosensors (nanobiosensors), can be used online and integrated into existing manufacturing process and distribution line or off-line as rapid, simple, and portable, as well as disposable, sensors for food contaminants. Food contaminants could be residues of pesticides, veterinary and human drugs, microbial toxins, preservatives, contaminants from food processing and packaging, and other residues. This milieu of compounds can pose difficulties in the detection of food contaminants. Nanosensors with their novel uses are the emerging method that could be used for the detection of many food contaminants, even mycotoxins and many food allergens. Whether it used as online or off-line, the nanosensor can be integrated with wireless technology and used for real-time transmission of contaminant alarm or test results to remote servers, providing rapid screening and reporting. Thus nanosensors are more cost-effective, rapid, and more sensitive than instrumental and conventional procedures. Recent developments in nanosensors may provide more applications for their use in food contaminant detection. The future role of these nanosensors will become even more important as the food laboratory is faced with the increasing pressure to reduce cost, time, and complexity. The objective of this chapter is to give a general overview of the possible application of nanosensors in the food contaminant detection and analysis.
Bakteri ureolitik adalah bakteri yang memiliki aktivitas enzim urease yang menghidrolisis urea un... more Bakteri ureolitik adalah bakteri yang memiliki aktivitas enzim urease yang menghidrolisis urea untuk menghasilkan karbondioksida dan amonia. Bakteri ini dapat diaplikasikan untuk agrikultur, kesehatan dan konstruksi. Penelitian ini bertujuan untuk melihat aktivitas urease Bacillus SP 34 dan Bacillus SP 83 dan kemampuannya menghasilkan kalsium karbonat. Pengujian aktivitas urease secara kuantitatif dilakukan dalam Nutrient Broth selama 18 jam. Produksi kalsit menggunakan medium NB-U/Ca inkubasi selama 7 hari. Hasil penelitian diketahui Bacillus SP 34 aktivitas urease yaitu 0,058 U/ml dan kalsium karbonat terbentuk 169.0 mg dan Bacillus SP 83 dengan aktivitas urease 0.065 U/ml dan kalsium karbonat terbentuk 105.0 g. Ke dua isolat ini dapat dikembangkan untuk bidang pertanian dan konstruksi sebagai bahan campuran beton.
A fluorescence-based fiber optic toxicity biosensor based on genetically modified Escherichia col... more A fluorescence-based fiber optic toxicity biosensor based on genetically modified Escherichia coli (E. coli) with green fluorescent protein (GFP) was developed for the evaluation of the toxicity of several hazardous heavy metal ions. The toxic metals include Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(III). The optimum fluorescence excitation and emission wavelengths of the optical biosensor were 400 ± 2 nm and 485 ± 2 nm, respectively. Based on the toxicity observed under optimal conditions, the detection limits of Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(III) that can be detected using the toxicity biosensor were at 0.04, 0.32, 0.46, 2.80, 100, 250, 400, 720 and 2600 μg/L, respectively. The repeatability and reproducibility of the proposed biosensor were 3.5%-4.8% RSD (relative standard deviation) and 3.6%-5.1% RSD (n = 8), respectively. The biosensor response was stable for at least five weeks, and demonstrated higher sensitivity towards metal toxicity evaluation when compared to a conventional Microtox assay.
In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxici... more In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri) encapsulated in alginate microspheres is described. Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(II) were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor. The loss of bioluminescence response from immobilized A. fischeri bacterial cells corresponds to changes in the toxicity levels. The inhibition of the luminescent biosensor response collected at excitation and emission wavelengths of 287 ± 2 nm and 487 ± 2 nm, respectively, was found to be reproducible and repeatable within the relative standard deviation (RSD) range of 2.4-5.7% (n = 8). The toxicity biosensor based on alginate micropsheres exhibited a lower limit of detection (LOD) for Cu(II) (6.40 μg/L), Cd(II) (1.56 μg/L), Pb(II) (47 μg/L), Ag(I) (18 μg/L) than Zn(II) (320 μg/L), Cr(VI) (1,000 μg/L), Co(II) (1700 μg/L), Ni(II) (2800 μg/L), and Fe(III) (3100 μg/L). Such LOD values are lower when compared with other previous reported whole cell toxicity biosensors using agar gel, agarose gel and cellulose membrane biomatrices used for the immobilization of bacterial cells. The
The basic concept of environmental toxicity and its importance in the evaluation of ecosystem hea... more The basic concept of environmental toxicity and its importance in the evaluation of ecosystem health will be introduced. Toxicity evaluation theory and practice will be briefly discussed. Traditional techniques such as bioassays for environmental toxicity evaluation will be introduced where the advantages and disadvantages will be presented. But the main focus of environmental toxicity evaluation will be on the use of more recent techniques for rapid environmental toxicity assessments such as toxicity biosensor and its basic concept, current applications, and future prospects.
Journal of Information Technology Education-Research, 2021
Aim/Purpose The purposes of this research are to analyze online learning management activities co... more Aim/Purpose The purposes of this research are to analyze online learning management activities conducted by the principals of junior high schools in Indonesia in facing COVID-19 as well as to discuss their perspective and expectations towards online learning activities when facing COVID-19 and after COVID-19 has passed. Background Due to the rapid spread of the COVID-19 pandemic, the Indonesian Minister of Education and Culture instructed that teaching and learning activities for all levels of education in Indonesia must be carried out online from home. There have been comprehensive reports about the various forms of online learning, its effects on students, the challenges, the learning transition from offline to online, and teachers' views on this new approach. Very few, if any, focus on how principals act upon the transition during this COVID-19 pandemic. Therefore, this research focuses on how principals overcome various problems that arise in the implementation of online lea...
This study aims to analyze Distance Learning (PJJ) online science teacher candidate students in P... more This study aims to analyze Distance Learning (PJJ) online science teacher candidate students in Pekanbaru City during the COVID-19 Pandemic. This research is a survey research with the type of public opinion survey. Sampling was taken through purposive sampling method. The data collected is ordinal data via e-questionnaire (Google form), through a summative response scale using a modified Likert scale with 4 answer choices. The results showed that the form of learning during the pandemic using various dominant applications were Google Meet (22.47%), Google Classroom (17.95%), WhatsApp (15.56%), and Schoology (11.70%). Online PJJ is not effectively carried out based on the availability of infrastructure, convenience and accessibility, difficulty in lecture materials, time, increased competence, and variety of courses. The implementation of PJJ is in accordance with the learning objectives because lecturers vary the use of applications, interactions run smoothly, and lecturers motivat...
Since the corona virus disease (Covid-19) was found in patients in Wuhan, China and this virus ha... more Since the corona virus disease (Covid-19) was found in patients in Wuhan, China and this virus has shown rapid transmission and has become a worldwide epidemic. As a result, online learning is applied to all universities in Indonesia by using various applications. This work is aimed for analyzing the implementation of online learning during the Covid -19 pandemic and is directed for investigating the form, implementation and expectations of students in online learning. This research was involved 231 samples consisting of all chemistry education student at Universities in Riau. The data directly collected through e-questionnaire using google form. The data obtained from the questionnaire were analyzed quantitatively and the interview data in the form of short questions were analyzed qualitatively. All the obtained data were carfully described in descriptive form. Basid oh the analysis, it was found that the type of online learning was dominated by using google classroom and zoom meet...
This study aims to produce an online learning evaluation instrument that is considered feasible b... more This study aims to produce an online learning evaluation instrument that is considered feasible by material experts, evaluation experts and through item analysis and user response questionnaires. This research was conducted with a 4D development model. The instruments used in this study were the material expert's feasibility assessment sheet, evaluation expert, item analysis and user response questionnaires, namely lecturers and students. The data analysis in this study used a rating scale and the item analysis used the product-moment, Kuder-Richardson, the discrimination power and the difficulty level of the questions. Through the item analysis of the 25 questions selected 10 questions that meet the discrimination power,difficulty level, validation and reliability. The reliability coefficient is 0.851 which is classified as high reliability. Meanwhile, the evaluation of material experts was 85.4%, expert evaluation was 88%, student response was 90.7% and lecturers were 90%. Bas...
The research aims to determine the effect of learning style on students’ performance through onli... more The research aims to determine the effect of learning style on students’ performance through online learning during the Covid-19 pandemic. The subjects of study are 269 chemistry education students at three universities in Indonesia. The data collection of learning style uses a Likert scale questionnaire, and learning performance is obtained from students’ grade point average. In this research, students’ learning style was divided into visual, auditorial, and kinesthetic. Data were analyzed using descriptive statistics with linear regression and ANOVA tests. The learning styles positively affect student learning performance by 4.7%, while 95.3% of other factors are not examined in this study. The learning performance of students with auditory is higher than visual and kinesthetic learning styles. Based on the inferential analysis, there is no significant difference in student learning performance based on student learning styles. Therefore, students with different learning styles ha...
Proceedings of the 1st International Conference on Education, Humanities, Health and Agriculture, ICEHHA 2021, 3-4 June 2021, Ruteng, Flores, Indonesia
This study aims to describe and analyze about: forms of e-learning-based distance learning activi... more This study aims to describe and analyze about: forms of e-learning-based distance learning activities carried out at the Department of Social Studies FKIP Riau. This type of research is descriptive qualitative research. The data to be collected is ordinal data, which comes from the results of e-questionnaires(google form). The data collected is summative response scale,using a modified Likert scale with 3 answer options. Student responses are organized based on 3 levels of Likert Scale: 1 = Yes; 2 = No; 3 = Hesitation. The data obtained is then analyzed through a descriptive statistical analysis of percentages. The results showed that the form of implementation of distance learning activities carried out in the department of Social Sciences FKIP Riau University refers to the indicators of distance learning, namely: clear learning objectives, relevant to the needs, quality of education, efficient and effectiveness of the program, equality and expansion of learning opportunities, inde...
Peran mikroba endofit dalam memproduksi metabolit sekunder dengan kualitas yang hampir sama denga... more Peran mikroba endofit dalam memproduksi metabolit sekunder dengan kualitas yang hampir sama dengan tanaman aslinya sangat potensial untuk dikembangkan. Penelitian ini bertujuan untuk menyelidiki bakteri endofit yang terdapat didalam jaringan kulit batang Laban (Vitex pubescens Vahl) serta kemampuannya untuk memproduksi metabolit bioaktif yang mempunyai aktivitas sitotoksik. Dalam penelitian ini digunakan teknik inokulasi langsung dengan jalan meletakkan sampel tanaman di atas permukaan Nutrient Agar (NA). Metoda Micro tetrazolium (MTT) digunakan untuk menetapkan aktivitas sitotoksik dari ekstrak etilasetat. Bakteri endofit yang berhasil diisolasi sebanyak 3 isolat yaitu Bakteri-2A, Bakteri -3B dan Bakteri-6C. Berdasarkan hasil penapisan dari 3 isolat tersebut didapatkan dua bakteri yang memiliki aktivitas potensial yang baik terhadap sel serviks (HeLa) yaitu isolat Bakteri – 6C (IC50 = 82.54 µg/mL) dan Bakteri-2A (IC50 = 297.09 µg/mL). Isolat yang menunjukkan aktivitas sitotoksik t...
Rapid determination of toxicity based on changes in the bioluminescent signal of marine bacterium... more Rapid determination of toxicity based on changes in the bioluminescent signal of marine bacterium Aliivibrio fischeri (A. fischeri) to evaluate toxicity of Ag(I) has been successfully developed. Assessment of toxicity was designed using inhibition of bioluminescent signal from A. fischeri bacteria, which was exposed with toxic material of Ag(I). This metal ion was utilized as a model of toxic material to evaluate the effects of cytotoxicity on bacteria cell. Measurement of bioluminescent were taken based on differences in bacterial cell signals before and after exposure to Ag(I) ion at an emission wavelength of 488±2 nm. The concentration of bacterial cell was used to assess the toxicity of Ag(I) at optical density (OD600 nm) of 0.78 Abs. The results found that the linear response of Ag toxicity was in the range of 0.05–10 mg/L, with EC50% of 8.42 mg/L for 4 minutes. The repeatability value within the relative standard deviation (RSD) was 2.5-4.7% (n=8). The results demonstrated th...
This article details an investigation on the mechanism of corrosion inhibition of mild steel usin... more This article details an investigation on the mechanism of corrosion inhibition of mild steel using amylose-acetate-blended carboxymethyl chitosan (AA-CMCh) in acidic media in the context of kinetic and thermodynamic parameters. The surface of mild steel was exposed to test solutions and evaluated using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The activation energy (Ea), free energy of adsorption (ΔG), enthalpy of activation (ΔHads), and entropy of activation (ΔSads) were determined in order to elucidate the mechanism of corrosion inhibition. The results confirmed that AA could be improved using CMCh as a corrosion inhibitor. The corrosion rate decreased from 1109.00 to 229.70 mdd (79.29%), while corrosion inhibition increased from 35.13 to 89.72%. Sulfate acid (H2SO4) of 0.25 M also helped in decreasing the corrosion rate from 2664.4 to 1041.67 mdd (60.9%) while also in increasing corrosion inhibition from 56.94 to 68.31%. The calculated val...
A tri-enzyme system consisting of choline kinase/choline oxidase/horseradish peroxidase was used ... more A tri-enzyme system consisting of choline kinase/choline oxidase/horseradish peroxidase was used in the rapid and specific determination of the biomarker for bacterial sepsis infection, secretory phospholipase Group 2-IIA (sPLA2-IIA). These enzymes were individually immobilized onto the acrylic microspheres via succinimide groups for the preparation of an electrochemical biosensor. The reaction of sPLA2-IIA with its substrate initiated a cascading enzymatic reaction in the tri-enzyme system that led to the final production of hydrogen peroxide, which presence was indicated by the redox characteristics of potassium ferricyanide, K₃Fe(CN)₆. An amperometric biosensor based on enzyme conjugated acrylic microspheres and gold nanoparticles composite coated onto a carbon-paste screen printed electrode (SPE) was fabricated and the current measurement was performed at a low potential of 0.20 V. This enzymatic biosensor gave a linear range 0.01-100 ng/mL (² = 0.98304) with a detection limit r...
An ultrasensitive electrochemical biosensor for the determination of pathogenic Vibrio cholerae (... more An ultrasensitive electrochemical biosensor for the determination of pathogenic Vibrio cholerae (V. cholerae) DNA was developed based on polystyrene-co-acrylic acid (PSA) latex nanospheres-gold nanoparticles composite (PSA-AuNPs) DNA carrier matrix. Differential pulse voltammetry (DPV) using an electroactive anthraquninone oligonucleotide label was used for measuring the biosensor response. Loading of gold nanoparticles (AuNPs) on the DNA-latex particle electrode has significantly amplified the faradaic current of DNA hybridisation. Together with the use of a reported probe, the biosensor has demonstrated high sensitivity. The DNA biosensor yielded a reproducible and wide linear response range to target DNA from 1.0 × 10 −21 to 1.0 × 10 −8 M (relative standard deviation, RSD = 4.5%, n = 5) with a limit of detection (LOD) of 1.0 × 10 −21 M (R 2 = 0.99). The biosensor obtained satisfactory recovery values between 91 and 109% (n = 3) for the detection of V. cholerae DNA in spiked samples and could be reused for six consecutive DNA assays with a repeatability RSD value of 5% (n = 5). The electrochemical biosensor response was stable and maintainable at 95% of its original response up to 58 days of storage period.
The present research describes a simple method for the identification of the gender of arowana fi... more The present research describes a simple method for the identification of the gender of arowana fish (Scleropages formosus). The DNA biosensor was able to detect specific DNA sequence at extremely low level down to atto M regimes. An electrochemical DNA biosensor based on acrylic microsphere-gold nanoparticle (AcMP-AuNP) hybrid composite was fabricated. Hydrophobic poly(n-butylacrylate-N-acryloxysuccinimide) microspheres were synthesised with a facile and well-established one-step photopolymerization procedure and physically adsorbed on the AuNPs at the surface of a carbon screen printed electrode (SPE). The DNA biosensor was constructed simply by grafting an aminated DNA probe on the succinimide functionalised AcMPs via a strong covalent attachment. DNA hybridisation response was determined by differential pulse voltammetry (DPV) technique using anthraquinone monosulphonic acid redox probe as an electroactive oligonucleotide label (Table ). A low detection limit at 1.0 × 10 -18 M with a wide linear calibration range of 1.0 × 10 -18 to 1.0 × 10 -8 M (R 2 = 0.99) can be achieved by the proposed DNA biosensor under optimal conditions. Electrochemical detection of arowana DNA can be completed within 1 hour. Due to its small size and light weight, the developed DNA biosensor holds high promise for the development of functional kit for fish culture usage.
Molecularly imprinted (MIP) polymeric microspheres are generally a more stable material for hormo... more Molecularly imprinted (MIP) polymeric microspheres are generally a more stable material for hormone sensing application.
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