Energy-Transfer-Based Dual-Mode PEC-ECL Biosensor for Acetamiprid Analysis Sensitized by Two-Step DNA Circuit Amplification
Huan Yang, Huan Wang, Po Wang, Qiumei Feng
Abstract
Sensitive and accurate determination of acetamiprid is highly desirable for guaranteeing food safety. In this Letter, an energy-transfer-based dual-mode biosensor was developed using zinc-based metal–organic frameworks (Zn-MOFs) acting as both photoelectrochemical (PEC) and electrochemiluminescent (ECL) donors and Pt@Cu 2 O cubic nanocrystals (CNs) as the energy acceptor for detecting acetamiprid. By integration of aptamer recognition with two-step DNA circuit amplification (entropy-driven DNA cycle and DNA walker), the detection of acetamiprid was converted into the assay of abundant intermediate DNA strands. With the help of nicking endonuclease, a large number of single-stranded DNAs was generated on the surface of Zn-MOFs, which were used as multifunctional PEC and ECL substrates. Through competitive hybridization, Pt@Cu 2 O CNs as broad-spectrum quenchers were introduced, thereby enabling changes in the PEC and ECL responses for acetamiprid quantitation. The experimental results proved that the combination of energy transfer, two-step DNA circuit amplification, and dual-mode sensing strategy achieved the sensitive and accurate analysis of acetamiprid, with low detection limits of 20.2 fM (PEC mode) and 17.5 fM (ECL mode) within a wide range from 0 to 1 × 10 –9 M. The excellent specificity, reproducibility, and practicality confirmed the potential application of the biosensor for pesticide-related food safety.