Alina Sekretaryova - Academia.edu (original) (raw)
Uploads
Papers by Alina Sekretaryova
N.B.: When citing this work, cite the original article.
Arrays of screen printed graphite microband electrodes as a versatile electroanalysis platform
Blood cholesterol is a very important parameter for the assessment of atherosclerosis and other l... more Blood cholesterol is a very important parameter for the assessment of atherosclerosis and other lipid disorders. The total cholesterol concentration in human blood should be less than 5.17 mM. Conc ...
Journal of the American Chemical Society, Jan 12, 2016
Single molecule enzymology provides an opportunity to examine details of enzyme mechanisms that a... more Single molecule enzymology provides an opportunity to examine details of enzyme mechanisms that are not distinguishable in biomolecule ensemble studies. Here we report, for the first time, detection of the current produced in an electrocatalytic reaction by a single redox enzyme molecule when it collides with an ultramicroelectrode. The catalytic process provides amplification of the current from electron-transfer events at the catalyst leading to a measurable current. This new methodology monitors turnover of a single enzyme molecule. The methodology might complement existing single molecule techniques, giving further insights into enzymatic mechanisms and filling the gap between fundamental understanding of biocatalytic processes and their potential for bioenergy production.
Analytica chimica acta, Jan 11, 2016
The monitoring of phenolic compounds in wastewaters in a simple manner is of great importance for... more The monitoring of phenolic compounds in wastewaters in a simple manner is of great importance for environmental control. Here, a novel screen printed laccase-based microband array for in situ, total phenol estimation in wastewaters and for water quality monitoring without additional sample pre-treatment is presented. Numerical simulations using the finite element method were utilized for the characterization of micro-scale graphite electrodes. Anodization followed by covalent modification was used for the electrode functionalization with laccase. The functionalization efficiency and the electrochemical performance in direct and catechol-mediated oxygen reduction were studied at the microband laccase electrodes and compared with macro-scale electrode structures. The reduction of the dimensions of the enzyme biosensor, when used under optimized conditions, led to a significant improvement in its analytical characteristics. The elaborated microsensor showed fast responses towards catec...
Biotechnology Advances, 2016
We present a brief overview of bioelectrocatalytic devices for in vitro health applications, incl... more We present a brief overview of bioelectrocatalytic devices for in vitro health applications, including food safety and environmental analysis, focusing on microelectrode- and microfluidic-based biosensors, paper-based point-of-care devices and wearable biosensors. The main hurdles and future perspectives are discussed. We then consider the role of electron transfer between a biocatalyst and an electrode in biosensor design. Brief descriptions of indirect, direct and mediated mechanisms are given. The principal strategies, as well as recent developments for modulation of electron transfer in biocatalytic systems are summarised. In conclusion, we highlight some of the challenges associated with improving these redox systems.
Biosensors and Bioelectronics, 2014
Analytical Chemistry, 2012
Analytical Chemistry, 2014
The use of extremely small working electrodes offers a variety of benefits for electroanalysis. T... more The use of extremely small working electrodes offers a variety of benefits for electroanalysis. The enhanced mass transport as a result of convergent diffusion is the most important advantage of microdimensional electrodes and results in improved of analytical performance The low detectable-currents problem can be solved by single microelectrode multiplication into an array, thus combining the advantages of enhanced mass transport and high output signals. The microband is one of the most cost-effective and easy-fabricated geometries for microelectrodes. The microband width is a critical microscopic dimension of the electrode, which maintains the dominance of convergent diffusion, whereas the microband length is macroscopic and ensures registration of high currents.Graphite screen-printing on a plastic support is a standard technology for large-scale production of low cost electrochemical devices. This has been combined with simple guillotine cutting to fabricate of microband arrays ...
N.B.: When citing this work, cite the original article.
Arrays of screen printed graphite microband electrodes as a versatile electroanalysis platform
Blood cholesterol is a very important parameter for the assessment of atherosclerosis and other l... more Blood cholesterol is a very important parameter for the assessment of atherosclerosis and other lipid disorders. The total cholesterol concentration in human blood should be less than 5.17 mM. Conc ...
Journal of the American Chemical Society, Jan 12, 2016
Single molecule enzymology provides an opportunity to examine details of enzyme mechanisms that a... more Single molecule enzymology provides an opportunity to examine details of enzyme mechanisms that are not distinguishable in biomolecule ensemble studies. Here we report, for the first time, detection of the current produced in an electrocatalytic reaction by a single redox enzyme molecule when it collides with an ultramicroelectrode. The catalytic process provides amplification of the current from electron-transfer events at the catalyst leading to a measurable current. This new methodology monitors turnover of a single enzyme molecule. The methodology might complement existing single molecule techniques, giving further insights into enzymatic mechanisms and filling the gap between fundamental understanding of biocatalytic processes and their potential for bioenergy production.
Analytica chimica acta, Jan 11, 2016
The monitoring of phenolic compounds in wastewaters in a simple manner is of great importance for... more The monitoring of phenolic compounds in wastewaters in a simple manner is of great importance for environmental control. Here, a novel screen printed laccase-based microband array for in situ, total phenol estimation in wastewaters and for water quality monitoring without additional sample pre-treatment is presented. Numerical simulations using the finite element method were utilized for the characterization of micro-scale graphite electrodes. Anodization followed by covalent modification was used for the electrode functionalization with laccase. The functionalization efficiency and the electrochemical performance in direct and catechol-mediated oxygen reduction were studied at the microband laccase electrodes and compared with macro-scale electrode structures. The reduction of the dimensions of the enzyme biosensor, when used under optimized conditions, led to a significant improvement in its analytical characteristics. The elaborated microsensor showed fast responses towards catec...
Biotechnology Advances, 2016
We present a brief overview of bioelectrocatalytic devices for in vitro health applications, incl... more We present a brief overview of bioelectrocatalytic devices for in vitro health applications, including food safety and environmental analysis, focusing on microelectrode- and microfluidic-based biosensors, paper-based point-of-care devices and wearable biosensors. The main hurdles and future perspectives are discussed. We then consider the role of electron transfer between a biocatalyst and an electrode in biosensor design. Brief descriptions of indirect, direct and mediated mechanisms are given. The principal strategies, as well as recent developments for modulation of electron transfer in biocatalytic systems are summarised. In conclusion, we highlight some of the challenges associated with improving these redox systems.
Biosensors and Bioelectronics, 2014
Analytical Chemistry, 2012
Analytical Chemistry, 2014
The use of extremely small working electrodes offers a variety of benefits for electroanalysis. T... more The use of extremely small working electrodes offers a variety of benefits for electroanalysis. The enhanced mass transport as a result of convergent diffusion is the most important advantage of microdimensional electrodes and results in improved of analytical performance The low detectable-currents problem can be solved by single microelectrode multiplication into an array, thus combining the advantages of enhanced mass transport and high output signals. The microband is one of the most cost-effective and easy-fabricated geometries for microelectrodes. The microband width is a critical microscopic dimension of the electrode, which maintains the dominance of convergent diffusion, whereas the microband length is macroscopic and ensures registration of high currents.Graphite screen-printing on a plastic support is a standard technology for large-scale production of low cost electrochemical devices. This has been combined with simple guillotine cutting to fabricate of microband arrays ...