A new non-enzymatic biosensor for the determination of bisphenol-A.

In this study, a new non-enzymatic carbon paste biosensor was developed for the determination of Bisphenol-A (BPA) based on Multiwalled Carbon Nanotube (MWCNT) modified Myoglobin (Mb). The measurement principle of the biosensor was developed based on the inhibition effect of BPA on the heme group of myoglobin in the presence of hydrogen peroxide. With the designed biosensor, measurements were taken in the potential range of (-0.

A novel mıcrobıal bıosensor system based on C. tropicalis yeast cells for selectıve determınatıon of L-Ascorbıc acid.

In this study, a novel microbial biosensor was developed for the selective determination of L-Ascorbic acid. In the construction of the microbial biosensor, lyophilized Candida tropicalis yeast cells were immobilized with o-aminophenol by forming a film layer on a platinum electrode surface using electropolymerization. L-Ascorbic acid was quantified on the basis of both amperometric and differential pulse voltammetry (DPV) methods using the biosensor.

The relation of innate and adaptive immunity with viral-induced acute asthma attacks: Focusing on IP-10 and cathelicidin.

Background: Despite growing evidence suggesting potential association between innate and adaptive immunity in viral-induced acute asthma, there is paucity of data in this area.

Objective: This study aimed to investigate the association of innate and adaptive immunity with acute asthma attacks by analysing the role of IFN-γ-inducible protein 10 (IP-10), TLR2, cathelicidin, vitamin D and cytokines.

Material And Methods: This prospective study included 33 patients with viral-induced acute asthma and 30 children with controlled asthma.

A new polyaniline-catalase-glutaraldehyde-modified biosensor for hydrogen peroxide detection.

A new biosensor based on catalase enzyme immobilized on electrochemically constructed polyaniline (PANI) film modified with glutaraldehyde has been developed for the determination of hydrogen peroxide (HO) in milk samples. Assembly processes of polyaniline and immobilization of the enzyme were monitored with the help of electrochemical impedance spectroscopy. Amperometric measurements have been performed at cathodic peak (-0.

MWCNT-cysteamine-Nafion modified gold electrode based on myoglobin for determination of hydrogen peroxide and nitrite.

In this work, a novel amperometric biosensor of hydrogen peroxide (H2O2) was developed based on the immobilization of myoglobin (Mb) on the surface of the multi-walled carbon nanotube (MWCNT) -Nafion-cysteamine (CA) modified gold electrode (Au) and its electrocatalytic activity was used for the determination of nitrite (NO2(-)). In the optimization studies, the best MWCNT and myoglobin amount were investigated. It was discovered at the experiments for the optimization of the working conditions that the buffer at this study as 50.

A microbial biosensor based on Lactobacillus delbruecki sp. bacterial cells for simultaneous determination of lactic and pyruvic acid.

The aim of this study was mainly to develop a microbial biosensor for the simultaneous determination of lactic acid and pyruvic acid. In developing biosensor, lyophilised Lactobacillus delbruecki sp. bacterial cells were immobilised with polypyrrole on a platin electrode surface using electropolymerization method.

Design of a multiwalled carbon nanotube-Nafion-cysteamine modified tyrosinase biosensor and its adaptation of dopamine determination.

In this work, a multiwalled carbon nanotube (MWCNT)-Nafion-cysteamine (CA) modified tyrosinase biosensor brings a new and original perspective to biosensor technology intended for the development of dopamine determination. Dopamine measurements were done at 0.2V with the amperometric method by the developed biosensor system.

Cysteamine-palladium complex ([Pd(μ-OAc)(ppy)]2, ppy:2-phenylpyridine, PhMe)-modified peroxidase biosensor immobilized on a gold electrode.

A new peroxidase biosensor was developed using cysteamine-palladium complex-modified gold electrode. The principle of the measurements is based on monitoring increase in the oxidation potential of palladium complex (at + 0.47 V vs Ag/AgCl) using amperometric detection.

A new pyruvate oxidase biosensor based on 3-mercaptopropionic acid/6-aminocaproic acid modified gold electrode.

In the biosensor construction, 3-mercaptopropionic acid (3-MPA) and 6-aminocaproic acid (6-ACA) were used for forming self-assembled monolayer (SAM) on a gold disc electrode and pyruvate oxidase was immobilized on the modified electrode surface by using glutaraldehyde. Biosensor response is linearly related to pyruvate concentration at 2.5-50 μM, detection limit is 1.

A novel non-competitive amperometric immunosensor by using thiourea-glutaraldehyde-modified gold electrode for immunoglobulin M detection.

A novel non-competitive amperometric immunosensor based on a self-assembled monolayer (SAM) of thiourea modified by a polymeric Schiff's base of glutaraldehyde on gold electrode has been developed for determination of IgM. Alkaline phosphatase (ALP)-conjugated monoclonal anti-mouse immunoglobulin M (IgM) antibody was selectively bound to IgM molecules onto the surface of the electrode. Electrochemical response arising from the catalytic reaction of alkaline phosphatase enzyme.

Alkaline phosphatase based amperometric biosensor immobilized by cysteamine-glutaraldehyde modified self-assembled monolayer.

Alkaline phosphatase (ALP) was immobilized with cross-linking agents glutaraldehyde and cysteamine by forming a self-assembled monolayer on a screen printed gold electrode. ALP converts p-nitrophenyl phosphate to p-nitrophenol and phosphate. p-Nitrophenol loses H(+) ion and turns into the negatively charged compound p-nitrophenolate at medium pH.

Voltammetric determination of epinephrine by White rot fungi (Phanerochaete chrysosporium ME446) cells based microbial biosensor.

The lyophilized biomass of White rot fungi (Phanerochaete chrysosporium ME446) was immobilized in gelatine using glutaraldehyde crosslinking agent on a Pt working electrode. The fungal cells retained their laccase activity under entrapped state. The immobilized cells were used as a source of laccase to develop amperometric epinephrine biosensor.

Sensitive nitrate determination in water and meat samples by amperometric biosensor.

This study describes a novel biosensor method for specific determination of nitrate in food and water samples by using nitrate reductase (NR) (EC 1.9.6.

Do copper ions activate tyrosinase enzyme? A biosensor model for the solution.

Some metal ions play a cofactor role for the activity of tyrosinase enzyme and one of them is copper ion. In this study an amperometric biosensor was developed in order to investigate the effect of the copper ions on the activity of tyrosinase enzyme. In the construction of the biosensor tyrosinase enzyme was immobilized on a Clark-type dissolved oxygen probe which was covered with a oxygen sensitive teflon membrane, by using a chemical covalent immobilization method based on gelatine and bifunctional reagent, glutaraldehyde.

Preparation and optimization of a bienzymic biosensor based on self-assembled monolayer modified gold electrode for alcohol and glucose detection.

The aim of this project was to develop a bienzymic biosensor, which was based on co-immobilization of alcohol oxidase and glucose oxidase on the same electrode by formation of self-assembled monolayer (SAM) for selective determination of ethanol and glucose. In the biosensor construction the enzymes and the mediator, tetrathiafulvalene (TTF), were immobilized with cross-linking agents glutaraldehyde and cysteamine by forming a self-assembled monolayer (SAM) on a gold disc electrode. Amounts of ethanol and glucose were amperometrically detected by monitoring current values at reduction potential of TTF(+), 0.

A mediated polyphenol oxidase biosensor immobilized by electropolymerization of 1,2-diamino benzene.

A biosensor based on a partially purified polyphenol oxidase (PPO) enzyme was developed by using electropolymerization of [(2,2'-bipyridine)(chloro)(p-cymene)rutenium(II)]chloride] mediator complex and 1,2-diamino benzene (DAB) on a screen printing Pt electrode (1mm diameter). The electropolymerization was carried out at +0.7V for 45min in phosphate buffer (50mM, pH 7.

An inhibition type amperometric biosensor based on tyrosinase enzyme for fluoride determination.

In this study, a new biosensor based on the inhibition of tyrosinase for the determination of fluoride is described. To construct the biosensor tyrosinase was immobilized by using gelatine and cross-linking agent glutaraldehyde on a Clark type dissolved oxygen (DO) probe covered with a teflon membrane which is sensitive for oxygen. The phosphate buffer (50mM, pH 7.

Development of a catalase based biosensor for alcohol determination in beer samples.

An amperometric biosensor based on catalase enzyme for alcohol determination was developed. To construct the biosensor catalase was immobilized by using gelatin and glutaraldehyde on a Clark type dissolved oxygen (DO) probe covered with a teflon membrane which is sensitive for oxygen. The working principle of the biosensor depends on two reactions, which one is related to another, catalyzed by catalase enzyme.

A biosensor based on urate oxidase-peroxidase coupled enzyme system for uric acid determination in urine.

A new amperometric biosensor based on urate oxidase-peroxidase coupled enzyme system for the specific and selective determination of uric acid in urine was developed. Commercially available urate oxidase and peroxidase were immobilized with gelatin by using glutaraldehyde and fixed on a pretreated teflon membrane. The method is based on generation of H(2)O(2) from urine uric acid by urate oxidase and its consuming by peroxidase and then measurement of the decreasing of dissolved oxygen concentration by the biosensor.

A mushroom (Agaricus bisporus) tissue homogenate based alcohol oxidase electrode for alcohol determination in serum.

To construct homogenized tissue based biosensors by using plant tissue materials is a relatively new development in the biosensor technology. In this study, a homogenized mushroom (Agaricus bisporus) tissue based electrode in which alcohol oxidase activity was developed by immobilizing with gelatin and cross-linking agent glutaraldehyde at dissolved oxygen probe for determination of ethyl alcohol. The electrode response depends linearly on ethyl alcohol concentration between 0.

A new enzyme electrode based on ascorbate oxidase immobilized in gelatin for specific determination of l-ascorbic acid.

A biosensor for the specific determination of l-ascorbic acid in fruit juices and vitamin C tablets was developed using ascorbate oxidase (EC 1.10.3.

A novel biosensor based on activation effect of thiamine on the activity of pyruvate oxidase.

A biosensor based on pyruvate oxidase (POX) enzyme was developed for the investigation of the effect of thiamine (vitamin B(1)) molecule on the activity of the enzyme. The biosensor was prepared with a chemical covalent immobilization method on the dissolved oxygen (DO) probe by using gelatin and cross-linking agent, glutaraldehyde. POX catalyzes the degradation of pyruvate to acetylphosphate, CO(2) and H(2)O(2) in the presence of phosphate and oxygen.

Sensitive determination of L-lysine with a new amperometric microbial biosensor based on Saccharomyces cerevisiae yeast cells.

A new amperometric microbial biosensor based on Saccharomyces cerevisiae NRRL-12632 cells, which had been induced for lysine oxidase enzyme and immobilized in gelatin by a cross-linking agent was developed for the sensitive determination of L-lysine amino acid. To construct the microbial biosensor S. cerevisiae cells were activated and cultured in a suitable culture medium.

Whole cell immobilized amperometric biosensor based on Saccharomyces cerevisiae for selective determination of vitamin B1 (thiamine).

A new amperometric whole cell biosensor based on Saccharomyces cerevisiae immobilized in gelatin was developed for selective determination of vitamin B1 (thiamine). The biosensor was constructed by using gelatin and crosslinking agent glutaraldehyde to immobilize S. cerevisiae cells on the Teflon membrane of dissolved oxygen (DO) probe used as the basic electrode system combined with a digital oxygen meter.

A novel amperometric biosensor based on artichoke (Cynara scolymus L.) tissue homogenate immobilized in gelatin for hydrogen peroxide detection.

A biosensor for specific determination of hydrogen peroxide was developed by using homogenized artichoke (Cynara scolymus L.) tissue in combination with a dissolved oxygen probe and applied in determination of hydrogen peroxide in milk samples. Artichoke tissue, which has catalase activity, was immobilized with gelatine by means of glutaraldehyde and fixed on a pretreated teflon membrane.