Fabrication of branched gold copper nanoalloy doped mesoporous graphitic carbon nitride hybrid membrane for surface-enhanced Raman spectroscopy analysis of carcinogens

Carcinogens in food samples show great potential threat to human health due to their wide distribution and high carcinogenicity. In this work, branched AuCu nanoalloy doped mesoporous graphitic carbon nitride hybrid membrane (mpg-C3N4/AuCu) was fabricated for SERS analysis of carcinogens including benzidine and zearalenone in food. The AuCu was in-situ grown on mpg-C3N4 to form mpg-C3N4/AuCu composites. The as-fabricated mpg-C3N4/AuCu membrane can effectively combined synergistic effect of localized surface plasmon resonance properties of branched AuCu nanoalloy and semiconductor characteristics of mpg-C3N4. The limit of detection for crystal violet is 1.0 ng/L with enhancement factor of 3.7 × 108. The mechanism of high SERS activity of mpg-C3N4/AuCu membrane was investigated by density functional theory simulations. The mpg-C3N4/AuCu membrane was used for direct determination of benzidine, and indirect determination of zearalenone with 3,3',5,5'-tetramethylbenzidine as markers in food. The limits of detection of SERS method were 0.14 and 0.03 μg/L for benzidine and zearalenone, respectively. It provides a new strategy for design and fabrication of high-quality SERS substrates for carcinogens analysis.