Preparation of Ag/NaA zeolite modified carbon paste electrode as a DNA biosensor

In this research, we reported a method for synthesis of NaA zeolite. NaA zeolite has been successfully prepared within 30 min by microwave heating without using any conventional hydrothermal treatment and due to the exchange process the silver-loaded NaA microsized zeolites was produced. The synthesized zeolite was characterized using X-ray diffraction, scanning electronic microscopy and FT-IR techniques. The modified carbon paste electrode was prepared by incorporation of Ag(I) zeolite in the carbon paste matrix. Differential pulse voltammetry (DPV) was employed for development of electrochemical DNA hybridization biosensors based on Ag/NaA zeolite modified carbon paste electrode (Ag/ZMCPE) and methylene blue (MB) as electroactive label was used. The sensors rely on immobilization of a 15-mer single stranded oligonucleotide probe for detection of target DNA, as a model. The hybridization event was evaluated by DPV. Moreover, Ag/ZMCPE showed better advantages than NaA zeolite modified carbon paste electrode (ZMCPE). Under optimized experimental conditions, limit of detection was calculated 4.00 x 10(-12) M. (C) 2013 Elsevier B.V. All rights reserved.