Amperometric Biosensor Based on Immobilization of Oxalate Oxidase in a Mucin/Chitosan Matrix

Abstract

An amperometric electrode for oxalate determination immobilizing the oxalate oxidase in a mucin/chitosan (muc/ chit) gel with glutaraldehyde as crosslinking agent is presented. The effect of muc/chit weight ratio and volume percent (vol.%) of glutaraldehyde was studied. A very low dynamic response was observed in the case of 100% chitosan with 5 vol.% crosslinking agent. The addition of mucin to chitosan for enzyme immobilization resulted in a biosensor with much better performance, concerning to dynamic response, sensitivity, and stability, with 75% of the initial response after two months. The ratio muc/chit 70/30 was considered optimum for the immobilization. A slight crosslinking and the incorporation of mucin largely influences the swelling and diffusion of the analyte; a direct effect of these properties on the calibration slope was found; the hydrophilic environment for the biomolecule also favor the enzymatic activity through a higher enzyme-substrate interaction.

An amperometric oxalate biosensor based on sorghum oxalate oxidase bound carboxylated multiwalled carbon nanotubes–polyaniline composite film

“…The detection limit of biosensor was 3.0 M, which is better/lower than that of any other earlier electrochemical oxalate biosensor (Sakaa and Vallon, 1994;Shimohigoshi and Karobe, 1996;Reddy and Vadgama, 1997;Milardovic et al, 2000aMilardovic et al, ,b, 2008Perez et al, 2001;Hong et al, 2003;Fiorito and Torresi, 2004;Fiorito et al, 2005;Capra et al, 2007;Benavidez et al, 2009;Mishra et al, 2009;Chaudhary and Pundir, 2010) with the exception of DO metric oxalate biosensor based on PVC membrane (1 M) prepared in our laboratory (Pundir and Phaugat, 2009) which had a drawback, interference by aerobic O 2 . In order to check the repeatability and reproducibility of the method, the oxalate content in same urine sample was determined five times on a single day (within batch) and again after storage at −20 • C for one week (between batch).…”

“…Therefore the demand for a simple, sensitive, accurate and rapid method has arrived. Over the past few years, various electrochemical methods for determination of oxalate based on the oxalate oxidase (OxOx) have been reported (Rahni and Guilbault, 1986;Assolant et al, 1987;Dinckaya and Telefoncu, 1993;Sezginturk and Dinckaya, 2003;Sakaa and Vallon, 1994;Shimohigoshi and Karobe, 1996;Reddy and Vadgama, 1997;Milardovic et al, 2000aMilardovic et al, ,b, 2008Perez et al, 2001;Hong et al, 2003;Fiorito and Torresi, 2004;Fiorito et al, 2005;Capra et al, 2007;Benavidez et al, 2009;Mishra et al, 2009;Pundir and Phaugat, 2009;Chaudhary and Pundir, 2010). However these OxOx based biosensors have some common drawbacks such as unstability due to leaching of enzyme from membrane/support, low conductivity and interference in electron communication.…”

Mucin and carbon nanotube-based biosensor for detection of glucose in human plasma

“…The proposed mechanism involves diffusion of the glucose to GOx within the network of a hydrogel, with subsequent enzymatic reaction and production of H 2 O 2 and gluconic acid. The hydrogen peroxide produced is transported by diffusion to the working Pt electrode where it is oxidized [10][11][12][13][14][15].…”

Accessing new biomedical applications by combining genetic design and chemical modification of elastin-like recombinamers

“…The appropriate choice of peptide sequence has led to the development of recombinant proteins that have been processed into materials for tissue engineering 36,104,112,113 , drug-delivery systems [35][36][37][38] , polymer dispersants 39 , physical gelling agents 40,111 , or biosensors [41][42][43] . However, we believe that the generation of meaningful elatstin-mimetic constructs for the screening of peptidases has not been stated.…”

“…Las implicaciones directas de la estructura en el autoensamblaje en polímeros de bloque anfifílicos y proteínas, junto a la posibilidad de generar interacciones hidrofóbicas 26,27 e hidrofílicas 28,29 , ha permitido cierto grado de control sobre estructuras jerárquicas, como micelas esféricas o cilíndricas, vesículas, membranas bimoleculares e hidrogeles [30][31][32][33] . Además, propiedades tales como la respuesta frente a estímulos como cambios de temperatura 27,34 o pH 35 , han dado como resultado la aplicabilidad de estos materiales en la ingeniería de tejidos 36 , sistemas para la administración de fármacos [35][36][37][38] , dispersantes de polímeros 39 , agentes gelificantes físicos 40 o biosensores [41][42][43] .…”