A novel MoS2@Ga-doped ZnO heterojunction SERS substrate for tetracycline detection in water and milk.

The misuse of antibiotics in the livestock industry and their improper discharge into natural water bodies threaten public health and ecological security. The sensitive and reliable detection of antibiotic pollution is crucial for preventing the associated damage. In this work, we proposed a MoS2@Ga-doped ZnO heterojunction-based surface-enhanced Raman scattering platform for antibiotic detection. The heterostructure facilitates the separation and transfer of photogenerated electron-hole pairs while suppressing their recombination. This enhances the interfacial charge transfer between the heterojunction and the target molecule, leading to a significant amplification of the molecular Raman signal. A simple mixing of the sample with the heterojunction enables highly sensitive detection of antibiotics. The sensing performance was evaluated by detecting tetracycline in water and milk, with limits of detection of 1.82 × 10-11 mol L-1 and 2.51 × 10-12 mol L-1 in these two matrices, respectively. Furthermore, this platform exhibited robust practicality, anti-interference capability and stability. These advantages highlight the platform's potential for accurate monitoring of antibiotics in different matrices.