Glucose biosensors have proved an enormous success and are used by a growing number of people wit... more Glucose biosensors have proved an enormous success and are used by a growing number of people with diabetes throughout the world. There are several other notable biosensor developments that are alr ...
Managers must make hard decisions in these recession-ridden days. Gone are the times when mere in... more Managers must make hard decisions in these recession-ridden days. Gone are the times when mere interest was sufficient grounds to attend a conference. Unless your presence is essential you are unlikely to succeed in justifying the time and expense involved. Thus the key meetings have expanded and the unfocussed or peripheral gathering has suffered traumatic decline.
Smart and flexible bioelectronics on graphene have emerged as a new frontier in the field of Rece... more Smart and flexible bioelectronics on graphene have emerged as a new frontier in the field of Received: ((will be filled in by the editorial staff)) Revised: ((will be filled in by the editorial staff))
The possibility of introducing a computationally-assisted method to study aptamerprotein interact... more The possibility of introducing a computationally-assisted method to study aptamerprotein interaction was evaluated with the aim of streamlining the screening and selection of new aptamers. Starting from information on the 15-mer DNA aptamer (5'-GGTTGGTGTGGTTGG-3') that binds to thrombin (TBA), a library of mutated DNA sequences (994 elements) was generated and screened using a molecular dynamics method to generate computationally-derived binding scores. The TBA and three other mutated oligonucleotides, selected on the basis of their binding score (best, medium, worst), were incorporated into Surface Plasmon Resonance (SPR) biosensors. By reducing the ionic strength (binding buffer, 50 mM TrisHCl pH 7.4, 140 mM NaCl, 1 mM MgCl 2 , diluted 1:50) in order to match the simulated condition, the analytical performances of the four oligonucleotide sequences were compared in terms of signal amplitude, sensitivity (slope), linearity (R 2) and reproducibility (CVav %). Thrombin was detected in the concentration range 0-50 nM with a minimum detectable amount of 5 nM. The experimental results indicated that slightly better performance was obtained using the mutated sequence with the best binding score, while a slightly worse performance was found using the mutated sequence with the worst binding score, in agreement with the simulation findings. The behaviours of the TBA and the mutated-2-sequence with medium binding score were very similar and intermediate between the other two sequences.
This thesis is submitted in partial fulfilment of the requirements for the degree of Doctor of Ph... more This thesis is submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in co-tutela between University of Firenze and University of Cranfield.
The high sensitivity and specificity of DNA hybridisation techniques makes them powerful tools fo... more The high sensitivity and specificity of DNA hybridisation techniques makes them powerful tools for environmental or clinical analysis. This work describes the development of a DNA piezoelectric biosensor for the detection of the hybridisation reaction. Attention was focused on the choice of the coating chemistry that could be used for the immobilisation of oligonucleotides onto the gold surface of the quartz crystal. Four immobilisation procedures were tested and compared considering the amount of immobilised probe, the extent of the hybridisation reaction, the possibility of regeneration and the absence of non-specific adsorption. All the experiments were performed with oligonucleotides of 25 bases (probe, target and non-complementary oligonucleotide).The four coating methods were all based on the use of self-assembled monolayers. Three of them employed the interaction between streptavidin and biotin for the immobilisation of a biotinylated probe.Results indicated that immobilisation of a biotinylated probe on streptavidin linked to a layer of carboxylated dextran provides higher sensitivity for the detection of the hybridisation reaction, absence of non-specific adsorption and a higher stability with respect to the regeneration step.
This review is focussed towards the development of acetylcholinesterase enzymatic based biosensor... more This review is focussed towards the development of acetylcholinesterase enzymatic based biosensors for the quantification of trace concentrations of highly toxic pesticides via their inhibitory effect on the enzyme. Initial results were obtained using wild-type enzymes which have a broad spectrum of susceptibility to a variety of pesticides. The sensitivity and selectivity of the enzyme activity was improved by development and screening of a wide range of mutant enzymes. Optimal enzymes were then exploited within a range of sensor formats. A range of immobilisation techniques including adsorption based approaches, binding via proteins and entrapment within conducting polymers were all studied. The incorporation of stabilisers and co-factors were utilised to optimise electrode performance and stability-with both planar and microelectrode geometries being developed. Reproducible quantification of pesticides could be obtained at concentrations down to 10-17 M, representing a detection limit hitherto unavailable.
The temperature, pH, stability and response characteristics of the GDH-based glucose sensor illus... more The temperature, pH, stability and response characteristics of the GDH-based glucose sensor illustrate its potential usefulness for a variety of practical applications. In particular, the high catalytic activity and oxygen insensitivity of this biosensor make it suitable for in vivo blood glucose monitoring in the management of diabetes.
Glucose biosensors have proved an enormous success and are used by a growing number of people wit... more Glucose biosensors have proved an enormous success and are used by a growing number of people with diabetes throughout the world. There are several other notable biosensor developments that are alr ...
Managers must make hard decisions in these recession-ridden days. Gone are the times when mere in... more Managers must make hard decisions in these recession-ridden days. Gone are the times when mere interest was sufficient grounds to attend a conference. Unless your presence is essential you are unlikely to succeed in justifying the time and expense involved. Thus the key meetings have expanded and the unfocussed or peripheral gathering has suffered traumatic decline.
Smart and flexible bioelectronics on graphene have emerged as a new frontier in the field of Rece... more Smart and flexible bioelectronics on graphene have emerged as a new frontier in the field of Received: ((will be filled in by the editorial staff)) Revised: ((will be filled in by the editorial staff))
The possibility of introducing a computationally-assisted method to study aptamerprotein interact... more The possibility of introducing a computationally-assisted method to study aptamerprotein interaction was evaluated with the aim of streamlining the screening and selection of new aptamers. Starting from information on the 15-mer DNA aptamer (5'-GGTTGGTGTGGTTGG-3') that binds to thrombin (TBA), a library of mutated DNA sequences (994 elements) was generated and screened using a molecular dynamics method to generate computationally-derived binding scores. The TBA and three other mutated oligonucleotides, selected on the basis of their binding score (best, medium, worst), were incorporated into Surface Plasmon Resonance (SPR) biosensors. By reducing the ionic strength (binding buffer, 50 mM TrisHCl pH 7.4, 140 mM NaCl, 1 mM MgCl 2 , diluted 1:50) in order to match the simulated condition, the analytical performances of the four oligonucleotide sequences were compared in terms of signal amplitude, sensitivity (slope), linearity (R 2) and reproducibility (CVav %). Thrombin was detected in the concentration range 0-50 nM with a minimum detectable amount of 5 nM. The experimental results indicated that slightly better performance was obtained using the mutated sequence with the best binding score, while a slightly worse performance was found using the mutated sequence with the worst binding score, in agreement with the simulation findings. The behaviours of the TBA and the mutated-2-sequence with medium binding score were very similar and intermediate between the other two sequences.
This thesis is submitted in partial fulfilment of the requirements for the degree of Doctor of Ph... more This thesis is submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in co-tutela between University of Firenze and University of Cranfield.
The high sensitivity and specificity of DNA hybridisation techniques makes them powerful tools fo... more The high sensitivity and specificity of DNA hybridisation techniques makes them powerful tools for environmental or clinical analysis. This work describes the development of a DNA piezoelectric biosensor for the detection of the hybridisation reaction. Attention was focused on the choice of the coating chemistry that could be used for the immobilisation of oligonucleotides onto the gold surface of the quartz crystal. Four immobilisation procedures were tested and compared considering the amount of immobilised probe, the extent of the hybridisation reaction, the possibility of regeneration and the absence of non-specific adsorption. All the experiments were performed with oligonucleotides of 25 bases (probe, target and non-complementary oligonucleotide).The four coating methods were all based on the use of self-assembled monolayers. Three of them employed the interaction between streptavidin and biotin for the immobilisation of a biotinylated probe.Results indicated that immobilisation of a biotinylated probe on streptavidin linked to a layer of carboxylated dextran provides higher sensitivity for the detection of the hybridisation reaction, absence of non-specific adsorption and a higher stability with respect to the regeneration step.
This review is focussed towards the development of acetylcholinesterase enzymatic based biosensor... more This review is focussed towards the development of acetylcholinesterase enzymatic based biosensors for the quantification of trace concentrations of highly toxic pesticides via their inhibitory effect on the enzyme. Initial results were obtained using wild-type enzymes which have a broad spectrum of susceptibility to a variety of pesticides. The sensitivity and selectivity of the enzyme activity was improved by development and screening of a wide range of mutant enzymes. Optimal enzymes were then exploited within a range of sensor formats. A range of immobilisation techniques including adsorption based approaches, binding via proteins and entrapment within conducting polymers were all studied. The incorporation of stabilisers and co-factors were utilised to optimise electrode performance and stability-with both planar and microelectrode geometries being developed. Reproducible quantification of pesticides could be obtained at concentrations down to 10-17 M, representing a detection limit hitherto unavailable.
The temperature, pH, stability and response characteristics of the GDH-based glucose sensor illus... more The temperature, pH, stability and response characteristics of the GDH-based glucose sensor illustrate its potential usefulness for a variety of practical applications. In particular, the high catalytic activity and oxygen insensitivity of this biosensor make it suitable for in vivo blood glucose monitoring in the management of diabetes.
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