Fluorimetric identification of sulfonamides by carbon dots embedded photonic crystal molecularly imprinted sensor array.

Identification of sulfonamides (SAs) residues in food is vital for human health. A set of 4-channel sensor array was constructed by carbon dots (CDs) embedded in photonic crystal molecularly imprinted (PCMIP@CDs) film which included 3 PCMIP@CDs units and 1 PCNIP@CDs unit to determine typical SAs: sulfadimethoxine, sulfathiazole, sulfaguanidine, sulfamethazine, sulfadiazine. Under the optimal conditions, the response time of the sensor array was only 200 s.

Spectrophotometric detection of fenthion in foods after extraction by magnetic zirconia.

A magnetic material, @, was used to enrich an organophosphorus pesticide, fenthion. After enrichment the @ was treated with NaOH to elute and hydrolyze fenthion. The hydrolysis products, orthophosphate ions, combine to molybdate ions to yield molybdophosphoric acid, which was further reduced with to obtain a blue phosphatemolybdate.