Terahertz metamaterial immunosensor based on nano Au film structure for detecting trace of chloramphenicol in milk.

The persistent, formidable sterilizing efficacy of Chloramphenicol (CAP) continues to promote its illicit use in the fields of aquaculture and animal husbandry, notwithstanding rigorous bans. In an effort to substantially reduce the adverse effects arising from CAP residues, an inexpensive and straightforward terahertz (THz) immunosensing platform that exploiting the nanoscale Au film metamaterial (AuF MM) coupled with an immunocompetitive assay. Small molecules of CAP-BSA anchor to the silicon-based AuF MM solid-phase substrate through hydrophobic interactions. Subsequently, these molecules and CAP standards participate in a competitive binding with colloidal gold (AuNPs) labeled-CAP monoclonal antibodies (mAb). The resulting change in spectral transmittance, caused by the THz waves' interaction with the refractive index response elicited by both the gold particles and the formed complexes on the AuF MM surface, is exploited for the qualitative assessment of CAP residues in milk. The heightened transmission of THz waves diminishes interference from the milk matrix, achieving satisfactory detection limits as low as 5 pg/mL. This demonstrates that we have effectively developed a straightforward yet efficacious strategy for THz detection that is both sensitive and specific. This strategy is anticipated to furnish a novel analytical method for the identification of proscribed molecules or deleterious viruses in foodstuffs and agricultural commodities. [ABSTRACT FROM AUTHOR]