The amperometric biosensor for urea determination is designed. decomposition product of produced by urease oxidized in an electrochemical way. specially developed carbon black (CB) paste electrode covered a semipermeable membrane containing immobilized urease. Three types the action are identified. At low working potentials (0-0.1 V), one electron oxidation carbamic acid can be monitored. Cation-radical whereupon undergoes dimerization to hydrazine. higher (0.2-0.5 electro-oxidation both and...

In this paper, we present a biosensor based on gold nanoparticle (AuNP)-modified Pt electrode with an adjusted membrane containing cross-linked L-amino acid oxidase for the detection and quantification of total acids. The designed was tested characterized using capacitance-based principle, capacitance measurements after polarization, disconnection from circuit, addition respective amount analyte. method implemented capacitive catalytic properties Pt/AuNP electrode; nanostructures were able...

Thermally reduced graphene oxide (TRGO) is a graphene-based nanomaterial that has been identified as promising for the development of amperometric biosensors. Urease, in combination with TRGO, allowed us to create mediator-free biosensor intention precise detection urea clinical trials. Beyond simplicity technology, exhibited high sensitivity (2.3 ± 0.1 µA cm−2 mM−1), great operational and storage stabilities (up seven months), appropriate reproducibility (relative standard deviation (RSD)...

Abstract An original concept in technology of biosensitive electrodes based on single‐wall carbon nanotubes (SWCNT) is proposed. According to a newly proposed technique the electrode surface consisting SWCNT’s embedded porous polycarbonate film was preoxidized enzymatically using laccase from Basidiomycete Lac . efficient electron transfer active centre PQQ‐dependent glucose dehydrogenase (s‐PQQ‐GDH) SWCNT allowed application s‐PQQ‐GDH as recognition element for reagentless biosensor design....

Abstract D‐fructose amount in food and beverages should be carefully controlled order to avoid its overconsumption by human, which can lead various metabolic diseases. Thus, the development of a low‐cost portable (bio)sensors, realize on‐site monitoring D‐fructose, is still highly required. In this work, we proposed several reagentless bioelectrochemical systems (BioESs) based on fructose dehydrogenase EC1.1.99.11 from Gluconobacter japonicus (FDH) 2‐arylamine‐1,4‐benzoquinone (ABQ)...

Investigations of L-glutamate release in living organisms can help to identify novel L-glutamate-related pathophysiological pathways, since abnormal transmission cause many neurological diseases. For the first time, a nitrogen-modified graphene oxide (GO) sample (RGO) is prepared through simple and facile one-pot hydrothermal reduction GO presence 20 wt.% dye malachite green used for amperometric biosensing. The biosensor demonstrates adequate stability easy prepare calibrate. detects...

Aldonic acids have already found many applications in food, pharmaceutical, and cosmetics industries there are new ones likely to come.

Surfaces of constituent parts biosensors based on single wall carbon nanotube layer were investigated and compare for properly functioning faulty biosensors. Though the original technology is acceptable changing selectivity, only glucose sensitive are investigated. Based results study, a correlation between features nanoscale structures parameters amperiometric assemblage which an innovative approach described. Original template electrodes has been prepared base deposited supporting...

As electrode nanomaterials, thermally reduced graphene oxide (TRGO) and modified gold nanoparticles (AuNPs) were used to design bioelectrocatalytic systems for reliable D-tagatose monitoring in a long-acting bioreactor where the valuable sweetener was enzymatically produced from dairy by-product D-galactose. For this goal D-fructose dehydrogenase (FDH) Gluconobacter industrius immobilized on these nanomaterials by forming three amperometric biosensors: AuNPs coated with 4-mercaptobenzoic...

The determination of L-glutamate in biological media is very important, as it the most common excitatory neurotransmitter related to some neurological diseases, such Parkinson's, communication dysfunction, stroke, epilepsy and schizophrenia. When aiming study pathways these well for evaluation medical treatments, important have rapid reliable methods L-glutamate. This presents new approach an enzyme-based biosensor operating at −0.1 V, which ensures its good sensitivity selectivity. reduced...

The aim of the study is to create a rapid and reliable biosensor for determining choline in biological media. Materials methods. Choline oxidase (EC 1.1.3.17, 17 U/mg) from Arthrobacter globiformis was purchased Sigma. Hydrogen peroxide (30 %, v/v aqueous solution), chloride, bovine serum albumin (V fraction) (BSA) were obtained Glutaraldehyde 25 % Merck KGaA. Semipermeable terylene membrane, 12 µM thickness, 0.4 diameter pore Institute Joint Nuclear Research. body fluid samples mice...

The prototype of amperometric biosensor for urea determination was designed. enzyme electrode, made of a specially developed modified graphite (MG) paste, produced by covering the electrode surface with adjustable membrane containing immobilized urease from Canavalia ensiformis (E.C. 3.5.1.5.). Simple methodology in real time has been proposed. experimental study and the mathematical model action have performed.

The idea of developing multi-parameter urea analyser comprising urea, Na+ and K+ selective electrodes has been considered. For this purpose the biosensors based on urease recombinant working in amperometric potentiometric way were developed. parameters both studied optimized. Possibilities real samples analysis using developed shown by measuring concentrations blood dialysate taken from patients with renal failure. Both demonstrated high degree signal reproducibility (the relative standard...

Abstract In the current work, PQQ‐dependent glucose dehydrogenase (s‐PQQ‐GDH) has been investigated as a potential biotin labeling agent. The conjugation of s‐PQQ‐GDH with was achieved according to newly proposed technique using commercially available pentafluorophenyl ester. residual activity conjugate about 90% against 100% native activity. suitability for amperometric immunoanalysis tested carbon (CE) and gold (Au) electrodes. An efficient electron transfer from active centre CE or Au...

In this study, PQQ-dependent glucose dehydrogenase (PQQ-GDH) was immobilized onto reduced graphene oxide (rGO) modified with organic dyes from three different classes (acridine, arylmethane, and diazo); namely, neutral red (NR), malachite green (MG), congo (CR) formed types of biosensors. All rGO/organic dye composites were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy. The impact modifications employed in bioelectrocatalytic systems on...

In this presentation, we will demonstrate creation process (R&D and engineering) of biosensor device for direct urea concentration measurement in industrial fertilizer samples. The analyzer is fully automatic, fast, not requiring professional assistance, compact mobile. breakthrough technology enabling the construction such amperometric electrode, re-purposed from suited monitoring hemodialysis patients developed earlier by our team. There no competitor – production supply companies have...