The quantification of ethanol in alcoholic beverages was performed by yeast cell-based conductome... more The quantification of ethanol in alcoholic beverages was performed by yeast cell-based conductometric biosensor. A membrane with yeast cells immobilized in 2% Ca-alginate gel was attached on gold planar electrodes. Changes in conductivity due to the specific consumption of ethanol by yeast cells were registered by the computer-controlled sensor system. The response time of the constructed microbial sensor was less than 5 min, linearity (in a logarithmic scale) was observed in the range of 5-100 mM alcohol concentration. It was established that pH value in their region from 5 to 8 did not influence the levels of initial signal. The increase of a buffer capacity in the sample results in the decrease of the biosensor output. The minimal detectable level of ethanol was 1 mM and the relative standard deviation appeared to be 10-12% for 15 repeated assays. When the system was operated and stored at 20-25 degrees C, the biosensor response was stable for only 3 days. However, when the micro...
The construction and performance of a novel enzyme based optical sensor for in situ continuous mo... more The construction and performance of a novel enzyme based optical sensor for in situ continuous monitoring of glucose in biotechnological production processes is presented. Sensitive optical coatings are formed from inorganic-organic hybrid polymers (ORMOCER®sORMOCER®: Trademark of Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V. in Germany.) combined with a flurophore (ruthenium complex) and an enzyme, and applied to lenses, declad
Caracterisation electrochimique des proprietes conductrices d’hybrides nanoparticules d’or/polyet... more Caracterisation electrochimique des proprietes conductrices d’hybrides nanoparticules d’or/polyethyleneimine/alcool polyvinylique/thermolysine. Application au developpement d’un biocapteur enzymatique
A simple and highly sensitive approach for the detection of the anti-neoplastic drug gemcitabine ... more A simple and highly sensitive approach for the detection of the anti-neoplastic drug gemcitabine is presented, based on a one-step electropolymerized molecularly imprinted microporous-metal-organic-framework. The sensitive layer was prepared by electropolymerization of the aniline moieties of p-aminothiophenol- gold nanoparticles on the surface of gold electrodes tethered with p-aminothiophenol, in the presence of gemcitabine as a template molecule. Experimental parameters that control the performance of the sensor were investigated and optimized. Under optimal conditions a calibration curve was obtained in the linear range from 3.8fM to 38nM with a limit of detection of 3fM. The obtained imprinted sensor has the advantages of easy manufacture, high sensitivity and selectivity and good reproducibility. Furthermore the feasibility of the proposed technique has been investigated on spiked serum samples and infusion solution containing gemcitabine.
A possibility of the creation of potentiometric biosensor by adsorption of enzyme urease on zeoli... more A possibility of the creation of potentiometric biosensor by adsorption of enzyme urease on zeolite was investigated. Several variants of zeolites (nano beta, calcinated nano beta, silicalite, and nano L) were chosen for experiments. The surface of pH-sensitive field-effect transistors was modified with particles of zeolites, and then the enzyme was adsorbed. As a control, we used the method of enzyme immobilization in glutaraldehyde vapour (without zeolites). It was shown that all used zeolites can serve as adsorbents (with different effectiveness). The biosensors obtained by urease adsorption on zeolites were characterized by good analytical parameters (signal reproducibility, linear range, detection limit and the minimal drift factor of a baseline). In this work, it was shown that modification of the surface of pH-sensitive field-effect transistors with zeolites can improve some characteristics of biosensors.
EbîsT(COO')-CH-CH2 -CH2 -S-CH3, and Met-H2N-CH(COO*)-CH2 -CH2 -S-CH3. The obtained results, t... more EbîsT(COO')-CH-CH2 -CH2 -S-CH3, and Met-H2N-CH(COO*)-CH2 -CH2 -S-CH3. The obtained results, taking into consideration the contribution of these parameters, permit to be made, the following considerations: -although the ratio of the reactants varied from 1 : 1 to 1 :6 , it hadn’t be obtained the combinations in which the ratio was bigger than 1 :2 , and, in conclusion, the nature of the specie which is being separed doesn’t always match the aûxture composition which enters the reaction; -the second parameter the pH of the environment in which the reaction takes place, İnfluences mostly the nature of Molybdenum’oxospecies. The experiments have been made on the whole scale of pH, only well defıned could be isolated by the reaction mixture, could be obtained not only in the pH interval 1-6. Ali the obtained combinations are presented under the form of yellow-green amorphouspowder (I and II) and white (III and IV). The small solubility of these combinations in organically solvents ma...
В даній роботі розроблено математичну модель потенціометричного біосенсору на основі зворотного і... more В даній роботі розроблено математичну модель потенціометричного біосенсору на основі зворотного інгібування ацетилхолінестерази для визначення афлатоксину В1. Для валідації моделі та порівняння використано існуючий потенціометричний біосенсор на основі іммобілізованої ацетилхолінестерази. Математична модель представлена системою диференційних рівнянь, які описують динаміку біохімічних реакцій, на яких ґрунтується робота біосенсору. Кожне рівняння описує концентрації ферменту, субстрату, інгібітору, продукту або концентрації фермент-субстратного, фермент-інгібіторного, фермент-субстрат-інгібіторного комплексів в залежності від часу. Система розв’язана чисельно за допомогою програмного забезпечення Wolfram Mathematica. Вхідними параметрами системи є початкові концентрації ферменту, субстрату та інгібітору (2×10-5 М ацетилхолінестерази, 4×10-3 М ацетилхолін хлориду та 0,2 мкг/мл афлатоксину В1 відповідно), які є експериментально розрахованими. Константи швидкостей ферментативних реакці...
Aim. Improvement of analytical characteristics of an enzyme biosensor based on new inexpensive pe... more Aim. Improvement of analytical characteristics of an enzyme biosensor based on new inexpensive perspective stainless steel electrodes using silicalite nanoparticles. Methods. Conductometric enzyme biosensor was used. Results. Three methods of glucose oxidase (GOx) immobilization were studied and compared: GOx adsorption on silicalite modified electrodes (GOx-SME); cross-linking by glutaraldehyde without silicalite (GOx-GA); GOx adsorption on SME along with cross-linking by glutaraldehyde (GOx-SME-GA). The GOx-SME-GA biosensors based on stainless steel electrodes were characterized by 12–25-fold higher sensitivity comparing with other bio-sensors. The developed GOx-SME-GA biosensors were characterized by good reproducibility of glucose biosen-sors construction (relative standard deviation (RSD) – 18 %), improved signal reproducibility (RSD of glucose determination was 7 %) and good storage stability (29 % loss of activity after 18 days). Conclusions. The method of enzyme immobilization using silicalite together with GA cross-linking sufficiently enhances the enzyme adsorp-tion on the stainless steel electrodes and improves the analytical parameters of biosensors. This method is found to be promising for further creation of other enzyme biosensors.
The aim of this work was to develop an array of biosensors for simultaneous determination of four... more The aim of this work was to develop an array of biosensors for simultaneous determination of four carbohydrates in solution. Several enzyme systems selective to lactose, maltose, sucrose and glucose were immobilised on the surface of four conductometric transducers and served as bio-recognition elements of the biosensor array. Direct enzyme analysis carried out by the developed biosensors was highly sensitive to the corresponding substrates. The analysis lasted 2 min. The dynamic range of substrate determination extended from 0.001 mM to 1.0–3.0 mM, and strongly depended on the enzyme system used. An effect of the solution pH, ionic strength and buffer capacity on the biosensors responses was investigated; the conditions of simultaneous operation of all biosensors were optimised. The data on cross-impact of the substrates of all biosensors were obtained; the biosensor selectivity towards possible interfering carbohydrates was tested. The developed biosensor array showed good signal reproducibility and storage stability. The biosensor array is suited for simultaneous, quick, simple, and selective determination of maltose, lactose, sucrose and glucose.
Different modifications of the zeolites Na +-Beta and LTA were applied for improving the working ... more Different modifications of the zeolites Na +-Beta and LTA were applied for improving the working characteristics of a urea biosensor. The bioselective membrane of the biosensor was based on urease and different zeolites co-immobilized with bovine serum albumin on the surface of a pH-FET. It was shown that the biosensors modified with the zeolites H +-Beta30 and H +-Beta50 are characterized by increased sensitivity to urea. The influence of the zeolite concentration on the sensitivity of the biosensors was studied. The optimal concentration of the zeolites H +-Beta30 and H +-Beta50 in the bioselective membrane was 15 %. Different variants of co-immobilization of urease and zeo-lite H +-Beta30 were studied and the optimal method was selected. Thus, a general conclusion is that the urea bio-sensor sensitivity can be improved using zeolite H +-Beta30 for urease immobilization in the bioselective membrane .
The quantification of ethanol in alcoholic beverages was performed by yeast cell-based conductome... more The quantification of ethanol in alcoholic beverages was performed by yeast cell-based conductometric biosensor. A membrane with yeast cells immobilized in 2% Ca-alginate gel was attached on gold planar electrodes. Changes in conductivity due to the specific consumption of ethanol by yeast cells were registered by the computer-controlled sensor system. The response time of the constructed microbial sensor was less than 5 min, linearity (in a logarithmic scale) was observed in the range of 5-100 mM alcohol concentration. It was established that pH value in their region from 5 to 8 did not influence the levels of initial signal. The increase of a buffer capacity in the sample results in the decrease of the biosensor output. The minimal detectable level of ethanol was 1 mM and the relative standard deviation appeared to be 10-12% for 15 repeated assays. When the system was operated and stored at 20-25 degrees C, the biosensor response was stable for only 3 days. However, when the micro...
The construction and performance of a novel enzyme based optical sensor for in situ continuous mo... more The construction and performance of a novel enzyme based optical sensor for in situ continuous monitoring of glucose in biotechnological production processes is presented. Sensitive optical coatings are formed from inorganic-organic hybrid polymers (ORMOCER®sORMOCER®: Trademark of Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V. in Germany.) combined with a flurophore (ruthenium complex) and an enzyme, and applied to lenses, declad
Caracterisation electrochimique des proprietes conductrices d’hybrides nanoparticules d’or/polyet... more Caracterisation electrochimique des proprietes conductrices d’hybrides nanoparticules d’or/polyethyleneimine/alcool polyvinylique/thermolysine. Application au developpement d’un biocapteur enzymatique
A simple and highly sensitive approach for the detection of the anti-neoplastic drug gemcitabine ... more A simple and highly sensitive approach for the detection of the anti-neoplastic drug gemcitabine is presented, based on a one-step electropolymerized molecularly imprinted microporous-metal-organic-framework. The sensitive layer was prepared by electropolymerization of the aniline moieties of p-aminothiophenol- gold nanoparticles on the surface of gold electrodes tethered with p-aminothiophenol, in the presence of gemcitabine as a template molecule. Experimental parameters that control the performance of the sensor were investigated and optimized. Under optimal conditions a calibration curve was obtained in the linear range from 3.8fM to 38nM with a limit of detection of 3fM. The obtained imprinted sensor has the advantages of easy manufacture, high sensitivity and selectivity and good reproducibility. Furthermore the feasibility of the proposed technique has been investigated on spiked serum samples and infusion solution containing gemcitabine.
A possibility of the creation of potentiometric biosensor by adsorption of enzyme urease on zeoli... more A possibility of the creation of potentiometric biosensor by adsorption of enzyme urease on zeolite was investigated. Several variants of zeolites (nano beta, calcinated nano beta, silicalite, and nano L) were chosen for experiments. The surface of pH-sensitive field-effect transistors was modified with particles of zeolites, and then the enzyme was adsorbed. As a control, we used the method of enzyme immobilization in glutaraldehyde vapour (without zeolites). It was shown that all used zeolites can serve as adsorbents (with different effectiveness). The biosensors obtained by urease adsorption on zeolites were characterized by good analytical parameters (signal reproducibility, linear range, detection limit and the minimal drift factor of a baseline). In this work, it was shown that modification of the surface of pH-sensitive field-effect transistors with zeolites can improve some characteristics of biosensors.
EbîsT(COO')-CH-CH2 -CH2 -S-CH3, and Met-H2N-CH(COO*)-CH2 -CH2 -S-CH3. The obtained results, t... more EbîsT(COO')-CH-CH2 -CH2 -S-CH3, and Met-H2N-CH(COO*)-CH2 -CH2 -S-CH3. The obtained results, taking into consideration the contribution of these parameters, permit to be made, the following considerations: -although the ratio of the reactants varied from 1 : 1 to 1 :6 , it hadn’t be obtained the combinations in which the ratio was bigger than 1 :2 , and, in conclusion, the nature of the specie which is being separed doesn’t always match the aûxture composition which enters the reaction; -the second parameter the pH of the environment in which the reaction takes place, İnfluences mostly the nature of Molybdenum’oxospecies. The experiments have been made on the whole scale of pH, only well defıned could be isolated by the reaction mixture, could be obtained not only in the pH interval 1-6. Ali the obtained combinations are presented under the form of yellow-green amorphouspowder (I and II) and white (III and IV). The small solubility of these combinations in organically solvents ma...
В даній роботі розроблено математичну модель потенціометричного біосенсору на основі зворотного і... more В даній роботі розроблено математичну модель потенціометричного біосенсору на основі зворотного інгібування ацетилхолінестерази для визначення афлатоксину В1. Для валідації моделі та порівняння використано існуючий потенціометричний біосенсор на основі іммобілізованої ацетилхолінестерази. Математична модель представлена системою диференційних рівнянь, які описують динаміку біохімічних реакцій, на яких ґрунтується робота біосенсору. Кожне рівняння описує концентрації ферменту, субстрату, інгібітору, продукту або концентрації фермент-субстратного, фермент-інгібіторного, фермент-субстрат-інгібіторного комплексів в залежності від часу. Система розв’язана чисельно за допомогою програмного забезпечення Wolfram Mathematica. Вхідними параметрами системи є початкові концентрації ферменту, субстрату та інгібітору (2×10-5 М ацетилхолінестерази, 4×10-3 М ацетилхолін хлориду та 0,2 мкг/мл афлатоксину В1 відповідно), які є експериментально розрахованими. Константи швидкостей ферментативних реакці...
Aim. Improvement of analytical characteristics of an enzyme biosensor based on new inexpensive pe... more Aim. Improvement of analytical characteristics of an enzyme biosensor based on new inexpensive perspective stainless steel electrodes using silicalite nanoparticles. Methods. Conductometric enzyme biosensor was used. Results. Three methods of glucose oxidase (GOx) immobilization were studied and compared: GOx adsorption on silicalite modified electrodes (GOx-SME); cross-linking by glutaraldehyde without silicalite (GOx-GA); GOx adsorption on SME along with cross-linking by glutaraldehyde (GOx-SME-GA). The GOx-SME-GA biosensors based on stainless steel electrodes were characterized by 12–25-fold higher sensitivity comparing with other bio-sensors. The developed GOx-SME-GA biosensors were characterized by good reproducibility of glucose biosen-sors construction (relative standard deviation (RSD) – 18 %), improved signal reproducibility (RSD of glucose determination was 7 %) and good storage stability (29 % loss of activity after 18 days). Conclusions. The method of enzyme immobilization using silicalite together with GA cross-linking sufficiently enhances the enzyme adsorp-tion on the stainless steel electrodes and improves the analytical parameters of biosensors. This method is found to be promising for further creation of other enzyme biosensors.
The aim of this work was to develop an array of biosensors for simultaneous determination of four... more The aim of this work was to develop an array of biosensors for simultaneous determination of four carbohydrates in solution. Several enzyme systems selective to lactose, maltose, sucrose and glucose were immobilised on the surface of four conductometric transducers and served as bio-recognition elements of the biosensor array. Direct enzyme analysis carried out by the developed biosensors was highly sensitive to the corresponding substrates. The analysis lasted 2 min. The dynamic range of substrate determination extended from 0.001 mM to 1.0–3.0 mM, and strongly depended on the enzyme system used. An effect of the solution pH, ionic strength and buffer capacity on the biosensors responses was investigated; the conditions of simultaneous operation of all biosensors were optimised. The data on cross-impact of the substrates of all biosensors were obtained; the biosensor selectivity towards possible interfering carbohydrates was tested. The developed biosensor array showed good signal reproducibility and storage stability. The biosensor array is suited for simultaneous, quick, simple, and selective determination of maltose, lactose, sucrose and glucose.
Different modifications of the zeolites Na +-Beta and LTA were applied for improving the working ... more Different modifications of the zeolites Na +-Beta and LTA were applied for improving the working characteristics of a urea biosensor. The bioselective membrane of the biosensor was based on urease and different zeolites co-immobilized with bovine serum albumin on the surface of a pH-FET. It was shown that the biosensors modified with the zeolites H +-Beta30 and H +-Beta50 are characterized by increased sensitivity to urea. The influence of the zeolite concentration on the sensitivity of the biosensors was studied. The optimal concentration of the zeolites H +-Beta30 and H +-Beta50 in the bioselective membrane was 15 %. Different variants of co-immobilization of urease and zeo-lite H +-Beta30 were studied and the optimal method was selected. Thus, a general conclusion is that the urea bio-sensor sensitivity can be improved using zeolite H +-Beta30 for urease immobilization in the bioselective membrane .
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