Bioinspired rose-petal-like SnS₂ semiconductor with sulphur vacancies for highly sensitive SERS detection of acetamiprid in vegetables and fruits.

Acetamiprid (ACE), a widely used neonicotinoid insecticide (NEO), poses potential health risks due to residue accumulation in fruits and vegetables. Herein, we report a SnS₂ microsphere semiconductor SERS substrate with abundant sulphur vacancies for rapid and highly sensitive ACE detection. The microspheres, formed via spontaneous self-assembly of nanosheets under solvothermal conditions, exhibit a rose-petal-like morphology (RPS-SnS₂) exploited as a bioinspired architecture for enhanced SERS performance. This hierarchical structure potentially facilitates molecular enrichment through capillary effects, while sulphur vacancies may promote charge transfer for SERS enhancement. Under optimised conditions, this method exhibits excellent linearity from 1.00 to 100 μg/kg, a low detection limit of ppb levels, and satisfactory recoveries (RSD < 3.44%). The substrate performance was validated in typical actual vegetables (Chinese cabbage, radish, broccoli, cauliflower, green onion) and fruits (apple and pear), demonstrating reliable, selective, and reproducible ACE detection. Comparison with LC-MS/MS showed no significant difference at the 95% confidence level. This bioinspired, sulphur-vacancy-rich SERS platform provides a validated approach for ACE screening in selected vegetable and fruit matrices, supporting further assessment of its broader applicability.