Effective adsorption and in-situ SERS detection of multi-target pesticides on fruits and vegetables using bead-string like Ag NWs@ZIF-8 core-shell nanochains

In-situ, real-time and sensitive detection of multiple pesticide residues in food is always an important issue in food safety. Herein, a novel multifunctional bead-string like Ag [email protected] imidazolate framework-8 (Ag [email protected]) core–shell nanochains was successfully synthesized and utilized as surface-enhanced Raman scattering (SERS) substrate for in-situ and simultaneous detection of pesticide residues. Due to the microporous framework structure of ZIF-8 shell and the plasmon property of Ag NWs core, the Ag [email protected] composite was demonstrated to have strong adsorption performance and high SERS activity (enhancement factor: 4.6 × 107). The Ag [email protected] based SERS strategy achieved sensitive detection of two water-insoluble pesticides methylparathion and carbaryl with detection limits as low as 7.6 × 10−9 M and 5.7 × 10−9 M, as well as the in-situ detection of multi-pesticide residues on fruits and vegetables with acceptable recovery ranged from 77.4 % to 117.5 %, demonstrating its great potential for in-situ and rapid detection of food contaminants.