A novel DNA-imprinted polymer with multiplex signal amplification for highly sensitive detection of Ag+

In this study, a novel imprinted electrochemical sensor was constructed by modifying deoxyribonucleic acid (DNA) for the detection of Ag + with high sensitivity and selectivity. Chitosan (CS) and Ag + template ions were mixed and used to modify a glassy carbon electrode, forming a composite CS-Ag + film. After CS-Ag + film crosslinking, gold nanoparticles (AuNPs) electrodeposition, and removal of Ag + templates, the imprinted sensor was prepared. A novel DNA-imprinted sensor was prepared by immobilizing Ag + DNA aptamers on the surface of AuNPs. The electroactive area, surface morphology and electrochemical reaction mechanism of the DNA-imprinted sensor were analyzed. The basic steps of the reaction were studied through electrochemical reaction kinetics analysis. The experimental results show that the DNA-imprinted electrochemical biosensor can quantitatively detect Ag + in the range of 10–50 nM (R 2  = 0.99695) with a limit of detection (LOD) of 8.25 nM (3σ/slope). The sensitivity of the electrochemical biosensor was 1.7473 × 10 −6 A/μM, and the effective area was 8.2121 cm 2 . The proposed novel DNA-imprinted sensor for detecting Ag + has high sensitivity and selectivity.