Detection of Pesticide Residue Acetamiprid by SERS Based on Aptamers Regulating Carbon Dots Catalytic Reactions

In this paper, surface-enhanced Raman scattering (SERS) method was combined with aptamers and carbon-based nanoenzymes to establish a method for the determination of agricultural residue acetamiprid (AC) in vegetables. Results showed that, under the conditions of 80 ℃ water bath, 20 min reaction time and concentration of CD_N/Ag1, trisodium citrate, AgNO₃, Apt, NaCl, VBB was 169.35 µg/L, 6.45 mmol/L, 0.90 mmol/L, 22.93 nmol/L, 12.90 mmol/L, 0.323 µmol/L respectively, the AC-Apt-CD_N/Ag1-AgNO₃-trisodium citrate-VBB system showed a good linear relationship between the increase of SERS peak strength at 1617 cm⁻¹ (ΔI_{1617 cm}$_{^{-1}}$) and the AC concentration in the range of 14.30~457.67 nmol/L. The coefficient of determination was 0.9967. The detection limit was 10.03 nmol/L. Based on this, a simple, rapid, highly sensitive and reproducible method for the determination of trace AC was established. When the concentration of acetamiprid was 85.80 nmol/L, co-existing substances Mg²⁺, Na⁺, Cu²⁺, Zn²⁺, Al³⁺, Ba²⁺, Fe³⁺, K⁺, NH₄⁺, CO₃²⁻, NO₃⁻, SO₄²⁻, Cl⁻, HCO₃²⁻, carbendazim, imidacloprid, atrazin, chlorpyrifos and acetone did not interfere with the determination at the concentration of 8.580 µmol/L, and Ca²⁺ did not interfere with the determination at the concentration of 6.864 µmol/L. The method was applied to the determination of AC in cabbage, cucumber and tomato. The recovery rate was 98.27%~101.78%, and the relative standard deviations were 2.31%, 0.83% and 1.69%. The method was feasible.