Development of Silicalite/Glucose Oxidase-Based Biosensor and Its Application for Glucose Determination in Juices and Nectars.

The application of silicalite for improvement of enzyme adsorption on new stainless steel electrodes is reported. Glucose oxidase (GOx) was immobilized by two methods: cross-linking by glutaraldehyde (GOx-GA) and cross-linking by glutaraldehyde along with GOx adsorption on silicalite-modified electrode (SME) (GOx-SME-GA). The GOx-SME-GA biosensors were characterized by a four- to fivefold higher sensitivity than GOx-GA biosensor.

Enzyme biosensor systems based on porous silicon photoluminescence for detection of glucose, urea and heavy metals.

A phenomenon of changes in photoluminescence of porous silicon at variations in medium pH is proposed to be used as a basis for the biosensor system development. The method of conversion of a biochemical signal into an optical one is applied for direct determination of glucose and urea as well as for inhibitory analysis of heavy metal ions. Changes in the quantum yield of porous silicon photoluminescence occur at varying pH of the tested solution due to the enzyme-substrate reaction.

Application of amperometric biosensors for analysis of ethanol, glucose, and lactate in wine.

This article presents the application of amperometric biosensors based on platinum printed electrodes SensLab and immobilized enzymes, alcohol oxidase, glucose oxidase, and lactate oxidase, for wine analysis. Created devices demonstrate linear response to ethanol, glucose, and lactate within the concentration range 0.3-20 mM, 0.

Analysis of the potato glycoalkaloids by using of enzyme biosensor based on pH-ISFETs.

The applicability of an enzyme biosensor based on pH-ISFETs for direct determination of total glycoalkaloids content in real potato samples, without any pre-treatment, is shown. The results of determination of the total glycoalkaloids concentrations in potato samples from different experimental varieties obtained by the biosensor are well correlated with the analogous data obtained by the HPLC method with standard complex sample pre-treatment procedure. The detection of total glycoalkaloids content by biosensors is reproducible, the relative standard deviation was around 3%.

Creatinine sensitive biosensor based on ISFETs and creatinine deiminase immobilised in BSA membrane.

A creatinine sensitive biosensor based on ion sensitive field-effect transistors (ISFETs) with immobilised creatinine deiminase (CD) is developed. CD is immobilised on the transducer surface by classical cross-linking with bovine serum albumin (BSA) in a glutaraldehyde (GA) vapour. The linear dynamic ranges of biosensors are between 0 and 5 mM creatinine concentration, and the sensor sensitivity depends on the sample buffer concentration.

Stimulation of human olfactory receptor 17-40 with odorants probed by surface plasmon resonance.

We report here the results of human olfactory receptor (OR) 17-40 stimulation with some odorants probed by means of the double-channel surface plasmon resonance platform NanoSPR-6. OR 17-40 tagged with N-terminal cmyc sequence was heterologously co-expressed with Galpha(olf) protein in yeast, and receptor-carrying nanosomes were prepared from yeast membrane fraction. Then, receptors were specifically captured via anti-cmyc antibody attached to the gold-coated substrate in orientated or random way.

Characterization of a yeast D-amino acid oxidase microbiosensor for D-serine detection in the central nervous system.

d-Serine is an endogenous ligand for N-methyl-d-aspartate (NMDA) receptors, and alterations in its concentration have been related to several brain disorders, especially schizophrenia. It is therefore an important target neuromodulator for the pharmaceutical industry. To monitor d-serine levels in vivo, we have developed a microbiosensor based on cylindrical platinum microelectrodes, covered with a membrane of poly-m-phenylenediamine (PPD) and a layer of immobilized d-amino acid oxidase from the yeast Rhodotorula gracilis (RgDAAO).

Enzyme biosensors based on ion-selective field-effect transistors.

The key theoretical principles of the work on ion-selective field-effect transistor connected with their application in bioanalytical practice, some specifics of modern microtechnologies for their creation, and measurement schemes with set-ups are discussed. The achievements in the creation of enzyme biosensors based on ion-selective field-effect transistors and prospects for their application are described in detail.

Sensitivity and specificity improvement of an ion sensitive field effect transistors-based biosensor for potato glycoalkaloids detection.

Butyryl cholinesterase of different origin along with variations of the time of enzyme immobilization on the potentiometric transducer surface is offered to control the ion sensitive field effect transistor (ISFET)-based biosensor sensitivity. Because butyryl cholinesterase has been already used to develop the sensors for heavy metals, organophosphorus/carbamate pesticides, and steroidal glycoalkaloids analysis, the present study has been focused on the investigation and adjustment of the ISFET-based biosensor specificity exclusively to the glycoalkaloids. Utilization of ethylendiaminetetracetate (a complexon of heavy metal ions) and phosphotriesterase (a highly efficient catalyst for the hydrolysis of organophosphorus compounds) enabled the highly specific determination of glycoalkaloids at the background of lead and mercury (up to 500 microM of ions concentration) and paraoxon (up to 100 microM of pesticide concentration).

Biosensors based on enzyme field-effect transistors for determination of some substrates and inhibitors.

This paper is a review of the authors' publications concerning the development of biosensors based on enzyme field-effect transistors (ENFETs) for direct substrates or inhibitors analysis. Such biosensors were designed by using immobilised enzymes and ion-selective field-effect transistors (ISFETs). Highly specific, sensitive, simple, fast and cheap determination of different substances renders them as promising tools in medicine, biotechnology, environmental control, agriculture and the food industry.

Development and optimisation of biosensors based on pH-sensitive field effect transistors and cholinesterases for sensitive detection of solanaceous glycoalkaloids.

Highly sensitive biosensors based on pH-sensitive field effect transistors and cholinesterases for detection of solanaceous glycoalkaloids have been developed, characterised and optimised. The main analytical characteristics of the biosensors developed have been studied under different conditions and an optimal experimental protocol for glycoalkaloids determination in model solution has been proposed. Using such a biosensor and an enzyme reversible inhibition effect, the total potato glycoalkaloids content can be determined within the range of 0.

Mixed urease/amphiphile LB films and their application for biosensor development.

The optimal conditions for the formation of a stable mixed urease/octadecylamine (ODA) film at the air-water interface are determined. This film is efficiently transferred onto the hydrophobized surface of a pH-ISFET, and the features of the urea enzymatic field-effect transistor (ENFET) are determined: detection limit 0.2 mM, response time 15 s, and dynamic range 0-20 mM.