Silver Nanoparticles Decorated Polyaniline Nanowires-Based Electrochemical DNA Sensor: Two-step Electrochemical Synthesis

In this work, silver nanoparticles decorated onto polyaniline nanowires were synthesized site-specifically onto Pt working electrodes (with only 0.8 mm2 area) using a novel, rapid, and effective electrochemical procedure: electropolymerization of PANi NWs and electrodeposition of AgNPs. The complementary properties of PANi NWs and AgNPs were obtained, including high surface area, high electrochemical activity, high biocompatibility, high chemical stability and good adhesion with the electrode surface. Obtained results showed advantages of the electrosynthesis method compared to traditional methods, which have difficulties in binding between modifying materials with electrode surfaces. The sensor surface modification with the PANi NWs/AgNPs material facilitated the probe DNA immobilization and improved the electrochemical signal of the DNA sensors. The detection limit of the sensors was 2.80 × 10−15 M. The DNA sensors exhibited advantages including direct detection, high sensitivity, good specificity, and potential miniaturization for development of lab-on-a-chip systems.