No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
Ethanol content in must grape by Alcohol Dehydrogenase biosensor based on doped-polyaniline modified screen printed electrodes
ResearchGate has not been able to resolve any citations for this publication.
In winemaking gluconic acid is an important marker for quantitative evaluation of grape infection by Botrytis cinerea. A screen-printed amperometric bienzymatic sensor for the determination of gluconic acid based on gluconate kinase (GK) and 6-phospho-D-gluconate dehydrogenase (6PGDH) coimmobilized onto polyaniline/poly (2-acrylamido-2-methyl-1-propanesulfonic acid; PANI-PAAMPSA) is reported in this study. The conductive polymer electrodeposed on the working electrode surface allowed the detection of NADH at low potential (0.1 V) with a linear range from 4 × 10-3 to 1 mM (R2 = 0.99) and a sensitivity of 419.44 nA∙mM-1. The bienzymatic sensor has been optimized with regard to GK/6PGDH enzymatic unit ratio and ATP/NADP+ molar ratio which resulted equal to 0.33 and 1.2, respectively. Under these conditions a sensitivity of 255.2 nA∙mM-1, a limit of detection of 5 μM and a Relative Standard Deviation (RSD) of 4.2% (n = 5) have been observed. Finally, the biosensor has been applied for gluconic acid measurements in must grape samples and the matrix effect has been taken into consideration. The results have been compared with those obtained on the same samples with a commercial kit based on a spectrophotometric enzyme assay and were in good agreement, showing the capability of the bienzymatic PANI-PAAMPSA biosensor for gluconic acid measurements and thus for the evaluation of Botrytis cinerea infection in grapes.
This paper proposes an automatic measurement system for monitoring of biological processes using amperometric biosensors in flow injection analysis. Whereas this kind of measurement usually requires intervention of human experts, the proposed system allows full automation of the measurement process. Both flow injection and analyte concentration measurement processes are managed without human interactions. In this paper, a first prototype of the system customized for winemaking process monitoring is described and characterized.
Two new nanocomposite structures (i) Glucose oxidase (GOx) entrapped within polyaniline (PANI) layer (GOx/PANI) and (ii) GOx, gold nanoparticles (Au-NPs) entrapped within PANI layer (GOx/Au-NPs/PANI) were developed. These structures were deposited on the surface of carbon rod electrodes and evaluated amperometrically. It was found that in all cases Au-NPs facilitated electron transfer (ET) and they showed a positive effect on the amperometric signals of all evaluated types of electrodes. The sensitivity, apparent Michaelis constants and some other characteristics of developed biosensors were determined and evaluated. Results illustrate that GOx/PANI and GOx/Au-NPs/PANI nanocomposites retain catalytic activity of glucose oxidase (GOx) and seem to be suitable for the design of amperometric biosensors. In addition we predict possible application of such nanocomposites for some other nanotechnological purposes including biomedical ones.
Amperometric screen printed nitrate reductase by Escherichia coli biosensors have been developed to detect nitrate ions. The effects of two different immobilization procedures of NaR and mediator (Azure A and Methyl viologen MV) to increase the performances (response time, sensitivity, stability) of the nitrate sensor have been studied. The best performances were registered by nitrate biosensor developed with a simultaneous cross-linking of enzyme and MV mixed BSA in in satured glutaraldehyde vapour. This biosensor showed the capability to detect nitrate residue levels lower than the European legislation one for a long storage stability (> 36 days) representing an applicable and cheap method for the analysis of nitrate ions in water and food samples.
Poly(aniline)–poly(vinylsulfonate) composite-coated glassy carbon electrodes are found to give stable and reproducible electrocatlytic responses to NAD(P)H in citrate–phosphate buffer at pH 7. Analysis of these amperometric responses as a function of NAD(P)H concentration, film thickness, electrode potential and rotation speed show that the reaction occurs within the film, rather than just at the outside, and that the reaction is reversibly inhibited by the oxidation product [NA(P)D
+
]. Based on a full kinetic analysis, rate constants for the various processes are determined.
Magnetic Fe3O4 nanoparticles were prepared by co-precipitation method and used to develop a reagentless disposable amperometric ethanol (EtOH) biosensor. The electrochemical characteristics of modified processes were analyzed by cyclic voltammetry (CV) and chronoamperometry (CA). Results showed that the presence of Fe3O4 nanoparticles could enhance the peak currents of redox species. Moreover, the alcohol biosensor exhibited an excellent sensitivity and fast response time for EtOH with a wide linear response range from 1.0 to 9.0mM.
A differential-type amperometric biosensor based on conventional thick-film technology has been developed for breath alcohol measurement. The amperometric breath alcohol biosensor utilizes the alcohol dehydrogenase (ADH) and nicotinamide adenine dinucleotide (NAD+) cofactor which produce reduced NADH as a product of the oxidation of alcohol. The biosensor was designed in a differential format consisting of a common Ag/AgCl reference electrode, an active working electrode containing the ADH, and the inactive working electrode containing only bovine serum albumin instead of the ADH. The differential signal between the active working electrode and the inactive working electrode minimized the interference from a large number of oxidizable species present in a person's breath. Prior to the amperometric measurement the biosensor was hydrated simply by dipping it into a phosphate buffer solution at pH 7.4. The NADH produced from the enzymatic reaction was oxidized at the working electrode biased at a potential of 470mV vs. an on-board Ag/AgCl reference electrode. The biosensor can measure a person's breath alcohol over the concentration range 20–800ppm routinely required in a test of drunken driving.
Currently, polymer thin films embedded with metal nanoparticles provided the suitable microenvironment for biomolecules immobilization retaining their biological activity with desired orientation, to facilitate electron transfer between the immobilized enzymes and electrode surfaces, better conformation and high biological activity, resultant in enhanced sensing performance. This article reviews focus on various methods for brief discussion of fabrication of metal nanoparticles-polymer hybrid materials and their applications in different electrochemical biosensors. The performance of hybrid materials based electrochemical biosensor can be improved by synergic properties of the metal nanoparticles and polymer network with biomolecules interface via engineering of morphology, particle size, effective surface area, functionality, adsorption capability and electron-transfer properties. These attractive features to hybrid materials are expected to find applications in a new generation of miniaturized, smart biochip devices.
We report the pH dependence of the electrochemical redox behavior of polyaniline (PANI) that is template synthesized with poly(2-acrylamido-2-methyl-1-propanesulfonic acid), PAAMPSA. Cyclic voltammetry and spectroelectrochemistry were used to assess the oxidation and protonation states of PANI−PAAMPSA. Stable and reversible pernigraniline−emeraldine−leucoemeraldine transitions extend beyond pH 7. Direct pernigraniline−leucoemeraldine transitions dominate in alkaline conditions; these transitions are stable and reversible between 7 and 10, extending the pH stability of PANI well beyond those previously reported.
A novel graphene oxide sheets/polyaniline/CdSe quantum dots (GO/PANi/CdSe) nanocomposites were successfully synthesized and used for the sensitive electrochemiluminescence (ECL) biosensing. The GO/PANi/CdSe nanocomposites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), ultraviolet-visible (UV-vis) absorption spectroscopy, photoluminescence (PL) spectroscopy and Fourier transform infrared (FTIR) spectroscopy. Finally, the nanocomposites were employed to construct the biosensor via layer-by-layer assembly for the ECL detection of Cytochrome C (Cyt C). The whole process was characterized by cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS). Experimental parameters such as the ratio of GO/PANi, the K(2)S(4)O(8) concentration and the pH value of electrolyte solution were studied to investigate the effect on the ECL intensity. Under the optimized conditions, the ECL intensity decreased linearly with the Cyt C concentrations in the range from 5.0×10(-8) to 1.0×10(-4)M with detection limit of 2.0×10(-8)M. Besides, the as-proposed biosensor exhibits high specificity, good reproducibility, and stability, and may be applied in more bioanalytical systems.
An amperometric ethanol biosensor was fabricated by integration of alcohol dehydrogenase (ADH) with meldola's blue (MB)/ordered mesoporous carbon (OMC) composite modified glassy carbon electrode (MB/OMC/GCE). The MB/OMC/GCE was highly sensitive for nicotinamide adenine dinucleotide (NADH) measurement (9.1±0.25 μA/mM) and gave a low detection limit of 0.21±0.02 μM. The ethanol biosensor exhibited a wide linear range up to 6 mM with a lower detection limit of 19.1±0.58 μM as well as a high sensitivity of 34.58±2.43 nA/mM without suffering any interference from some common electroactive compounds.
The direct electrochemical oxidation of beta-nicotinamide adenine dinucleotide (NADH) at clean electrodes proceeds through a radical cation intermediate at high overpotentials and is subject to rapid fouling. Consequently, there has been a considerable body of work over the last 20 years looking at ways in which to catalyse the reaction using a wide variety of different types of modified electrode. These studies have resulted in a good knowledge of the essential features required for efficient catalysis. In designing modified electrodes for NADH oxidation, it is not only important to identify suitable redox groups, which can catalyse NADH oxidation and can be attached to the electrode surface; it is also important to ensure facile charge transport between the immobilised redox sites in order to ensure that, in multilayer systems, the whole of the redox film contributes to the catalytic oxidation. One way to achieve this is by the use of electronically conducting polymers such as poly(aniline).
A novel amperometric ethanol biosensor was constructed using alcohol dehydrogenase (ADH) physically immobilized within poly(vinyl alcohol)-multiwalled carbon nanotube (PVA-MWCNT) composite obtained by a freezing-thawing process. It comprises a MWCNT conduit, a PVA binder, and an ADH function. The measurement of ethanol is based on the signal produced by beta-nicotinamide adenine dinucleotide (NADH), the product of the enzymatic reaction. The homogeneity of the resulting biocomposite film was characterized by atomic force microscopy (AFM). The performance of the PVA-MWCNT-ADH biocomposite modified glassy carbon electrode was evaluated using cyclic voltammetry and amperometry in the presence of NADH and in the presence of ethanol. The ethanol content in standard solutions was determined and a sensitivity of 196 nA mM(-1), a linear range up to 1.5mM, and a response time of about 8s were obtained. These characteristics allowed its application for direct detection of ethanol in alcoholic beverages: beer, red wine, and spirit.
- G A Rivas
- M D Rubianes
- M L Pedano
- N F Ferreyna
- G L Luque
- M C Rodriguez
- S A Miscoria
Rivas G.A., Rubianes M.D., Pedano M.L., Ferreyna N.F., Luque G.L., Rodriguez M.C., Miscoria S.A., 2007,
Carbon Nanotubes Paste Electrodes. A new Alternative for the Development of Electrochemical Sensors,
Electroanalysis, 19, 823-831