Well-ordered Au@Ag NBPs/SiO₂ nanoarray for sensitive detection of chloramphenicol via DNAzyme-assisted SERS sensing

Misuse of chloramphenicol (CAP) can lead to severe food safety issues. Therefore, the accurate and sensitive detection of CAP residues is important for public health. Herein, a convenient and reliable interfacial self-assembly technique was used to form a uniform Au@Ag nanobipyramids (NBPs) film on an ordered SiO₂ nanosphere array (SiO₂ NS), which served as a Raman-enhanced substrate. In conjunction with a deoxyribonucleic acid enzyme-induced signal amplification strategy, we developed a novel surface-enhanced Raman scattering (SERS) biosensor for the selective and sensitive detection of CAP. The biosensor exhibited a detection limit of 6.42 × 10^-13 mol·L^-1 and a detection range of 1.0 × 10^-12-1.0 × 10^-6 mol·L^-1. The biosensor could detect CAP in spiked milk samples with a high accuracy, and its recovery rates ranged from 97.88% to 107.86%. The as-developed biosensor with the advantages of high sensitivity and high selectivity offers a new strategy for the rapid, reliable and sensitive detection of CAP, rendering it applicable to food safety control.