Electrochemical potential enhanced EC-SERS sensor for sensitive and label-free detection of acetamiprid

Abstract

Label-free surface-enhanced Raman spectroscopy (SERS) holds promise for detecting pesticide residues, yet its broader application in food safety is limited by the weak affinity between pesticides and SERS substrates. This study introduces an electrochemical surface-enhanced Raman spectroscopy (EC-SERS) sensor that utilizes potential strengthened molecular interactions and Ag@SiO₂ nanospheres as SERS substrates, significantly enhancing the detection sensitivity for acetamiprid (AAP). The dense distribution of silver nanoparticles (Ag NPs) on the SiO₂ surfaces creates numerous “hot spots,” significantly improving the SERS performance for AAP detection. A potential of −0.5 V substantially boosts the SERS signal intensity for AAP compared to without applied potential, notably achieving a 4.3-fold increase at the 631 cm⁻¹ signal peak. Under optimal conditions, the EC-SERS method achieved a limit of detection (LOD) for AAP at 0.046 μM, spanning a linear range from 0.05 μM to 0.1 mM, which is 185 times more sensitive than conventional SERS approaches. When applied to vegetable samples, the method showed recoveries between 95.56 % and 109.33 %, with results corroborated by HPLC-MS analysis. Thus, this study provides an effective and facile strategy for the detection of AAP in the food safety field.