Delayed delivery of chromogenic substrate to nanozyme amplified aptamer lateral flow assay for acetamiprid

Abstract

Nanozyme amplified lateral flow assay (LFA) demonstrated many attractive performances than the traditional gold nanoparticles (AuNPs) based LFA, however, they required several additional operations to implement the catalytic reaction of substrate. In this work, a chromogenic substrate integrated and nanozyme amplified aptamer lateral flow assay (CSNLFA) was constructed through automatic delivery of chromogenic substrate on strip. By introducing a sucrose-fixed chromogenic substrate loaded fiber (SCF) onto the sample pad of LFA strip, the CSNLFA platform achieved automated sequential catalytic reaction of substrate oxidation deposition after Au@Pt nanozyme was fully captured at T line of strip. This design was applied in an acetamiprid aptamer LFA and the developed aptamer CSNLFA (Apt-CSNLFA) achieved a linear range of 1–150 ng/mL for acetamiprid with the limit of detection (LOD) of 0.17 ng/mL. The Apt-CSNLFA demonstrated similar analytical performance to the conventional aptamer NLFAs but eliminated the additional operations for catalytic signal amplification. In addition, the new method was applied to the detection of tomato samples spiked with acetamiprid. The recovery ranged from 95% to 106.4% was obtained, which demonstrated the high application potential in rapid detection of acetamiprid.