INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
A Protein-Resistant Matrix for Electrochemical Based Recognition Assays
DIEGO PALLAROLA; LUIS DOMENIANNI; GRACIELA PRIANO; FERNANDO BATTAGLINI
John Wiley & Sons, Inc
Año: 2007 vol. 19 p. 690 - 690
In this work, two well known polymers, carboxymethyl dextran and poly(ethyleneglycol), are used for easily producing a platform for electrochemical affinity assays, avoiding nonspecific adsorption of proteins. In this way, modified electrode surfaces able to bind a recognition agent are constructed through simple and reliable reactions. 24 and 70 KDa Carboxymethyl Dextrans (CMDex24 and CMDex70) were covalently attached to gold through 2-aminoethylthiol, allowing the fast electron transfer reaction of a redox mediator. Based on ellipsometry and amperometry results, the nonspecific adsorption of neutravidin-horseradish peroxidase (NHRP), a conjugate used as indicating molecule, was studied considering the physicochemical characteristics of the CMDex films. The experimental results show that CMDex70 produces a dense structure reducing drastically the nonspecific adsorption of NHRP, still allowing the access of the redox mediator. Poly(ethylene glycol) derivates, combined with CMDex, were also investigated. Methoxypolyethylene glycol succinate N-hydroxysuccinimide ester (MW: 5000 Da), combined with either CMDex 24 or 70, was found also to reduce the nonspecific interactions. Additionally, the specific binding of NHRP, and the effect of the film structure in the amperometric response, were established using electrodes modified covalently with the specific biotin counterpart.