Development of Sudan II sensor based on modified treated pencil graphite electrode with DNA, o-phenylenediamine, and gold nanoparticle bioimprinted polymer

A new type of molecularly imprinted polymer (MIP) sensor was synthesized through an efficient one-step electropolymerization technique. The ds-DNA and gold nanoparticles were electrochemically entrapped into poly-(o-phenylenediamine) film (molecularly bioimprinted polymer) deposited on the treated pencil graphite electrode (PGE). After the electrochemical treatment process of PGE, the effective surface area of the electrode was increased by formation of carbon nanoparticles. The morphology and performance of the bioimprinted polymer were characterized by atomic force microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy in detail. The factors influencing the performance of the bioimprinted sensor were studied and optimized. The modified electrode displayed good reproducibility, satisfactory stability and high sensitivity and selectivity compare to reported conventional DNA and MIP sensors. Additionally, the square wave voltammetric peak current was linear to Sudan II concentration in the range of 1.0-20.0 and 20.0-500.0 nmol L-1, with a detection limit of 0.3 nmol L-1. The sensor was applied successfully for the determination of Sudan II in chili and ketchup sauces with satisfactory precision (2.6-4.4% of RSD) and acceptable recoveries (90-107%), demonstrating its feasibility for practical application. (C) 2015 Elsevier B.V. All rights reserved.