A highly sensitive AgNPs/Ni₃(HHTP)₂ SERS substrate for the detection of food additives and pesticide residues

Abstract Surface-enhanced Raman scattering (SERS) is a spectroscopic technique that utilizes nanostructured substrates and is vital in food analysis. However, enhancing SERS substrates’ sensitivity and applicability remains a challenge. The conductive metal organic framework Ni 3 (HHTP) 2 has been widely used due to its excellent conductivity and porous structure. This study combines Ni 3 (HHTP) 2 ’s charge transfer properties with AgNPs’s localized surface plasmon resonance to create a highly sensitive SERS substrate. Firstly, rod-shaped Ni 3 (HHTP) 2 was prepared, and then a monolayer of AgNPs film was loaded on its surface. The substrate can detect crystal violet at a concentration of 10 −14 M, and Ni 3 (HHTP) 2 has a flat structure, coupled with AgNPs film, provided good detection uniformity (Relative Standard Deviation, RSD = 10.09%). Moreover, the substrate successfully detected food additives solutions, as well as the pesticide residues on fruit surfaces by bending. This substrate offers a rapid monitoring solution for food safety, facilitating real-time detection of contaminants in daily life.