Potentiometric-biomimetic sensor

For the purpose of determining low hydrogen peroxide concentrations, the authors have designed the most cost-effective and simple to use potentiometric-biomimetic sensors based on immobilized catalase mimics. These sensors possess high hydrodynamic properties and the fastest speed of response. Figure 8.3 shows experimental data on catalase activity of biomimetic electrode in 0.03% aqueous H202. For the sake of comparison, catalase activities of aluminum electrode and aluminum electrode with applied adhesive are also shown. 

The change of electrode potential (E) of the catalase reaction with time was measured by a voltmeter. pH and E values for aqueous hydrogen peroxide were determined simultaneously for possible correlations between pH metric and potentiometric results of enzymatic activity of catalase-biomimetic sensors. The electrochemical unit was also equipped with a magnetic mixer. 

Electrocatalytic groups such as porphyrins and phthalocyanines that act as supramolecular hosts for different metals and mimic the active sites of various proteins are commonly used in amperometric sensors [66,67]. A biomimetic sensor based on an artificial enzyme or synzyme has been demonstrated [68]. The artificial enzyme used in this study was a synthetic polymer (quaternised polyethyleneimine containing 10% primary amines) which decarboxylated oxaloacetate. The product carbon dioxide was detected potentiometrically via a gas membrane electrode. 

Abstract Brief historic introduction precedes presentation of main types of transducers used in sensors including electrochemical, optical, mass sensitive, and thermal devices. Review of chemical sensors includes various types of gas sensitive devices, potentiometric and amperometric sensors, and quartz microbalance applications. Mechanisms of biorecognition employed in biosensors are reviewed with the method of immobilization used. Some examples of biomimetic sensors are also presented. 

On the other hand, the molecular recognition by enzymes, which are also applied in the form of organelles, microorganisms and tissue slices, is accompanied by chemical conversion of the analyte to the respective products. Therefore this type of sensor is termed a metabolism sensor2. The initial state is usually reached when the analyte conversion is complete. With metabolism sensors, under certain conditions cosubstrates, effectors, and enzyme activities can be measured via substrate determination. Amperometric and potentiometric electrodes and thermistors are the preferred transducers, but in some cases optoelectronic sensors have also been used. With biomimetic sensors physical signals such as sound, stress, or light are measured through their ability to... 

A.H. Kamel, ETC. Moreira and M.G.F. Sales, Biomimetic sensor potentiometric system for doxycycline antibiotic using a molecularly imprinted polymer as an artificial recognition element. Sensor Lett., 9 (5) 1654-1660, 2011. 

ETC. Moreira, A.H. Kamel, J.R.L. Guerreiro and M.G.F. Sales, Man-tailored biomimetic sensor of molecularly imprinted materials for the potentiometric measurement of oxytet-racycline. Biosens. Bioelectron., 26 (2) 566-574,2010. 

Studies on ethanol trace detection in aqueous solutions were carried out in an electrochemical cell of peroxidase-mimetic sensor of the potentiometric type, consisting of a reference electrode (Ag/AgCl) and a biomimetic electrode. Redistilled water was used for the background solution. The biomimetic electrode was prepared by adhering hematin-containing meroxidase mimetic to aluminum foil with Pattex adhesive [7, 8],... 

M. Arvand and H.A. Sarnie, A biomimetic potentiometric sensor based on molecularly imprinted polymer for the determination of memantine in tablets. Drug Test. Anal, 5 (6) 461-467, 2013. 

M. Javanbakht, S.E. Fard, A. Mohammadi, M. Abdouss, M.R. Ganjali, P Norouzi and L. Safaraliee, Molecularly imprinted polymer based potentiometric sensor for the determination of hydroxyzine in tablets and biological fluids. Anal. Chim. Acta, 612 (1) 65-74,2008. M. Javanbakht, S.E. Fard, M. Abdouss, A. Mohammadi, M.R. Ganjali, R Norouzi and L. Safaraliee, A biomimetic potentiometric sensor using molecularly imprinted polymer for the cetirizine assay in tablets and biological fluids, Electroanalysis, 20 (18) 2023-2030, 2008. 

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