Single source precursor-enabled NiS nanosheets on flexible carbon cloth for sensitive electrochemical detection of chloramphenicol in food and biological matrix.

The successful low-temperature, in-situ solvothermal strategy for the direct growth of nickel sulfide (NiS) nanostructures on flexible, conductive carbon cloth (CC) using a single-source precursor, Ni[S₂P(OC₃H₇)₂] is reported. This solution-processed approach enables the formation of highly-quality, crystalline and stoichiometric NiS films with a distinctive fern-like, porous nanosheet morphology, providing abundant electroactive sites and facilitating rapid electron transfer. The as-fabricated NiS/CC electrode exhibits excellent electrochemical sensing performance toward CAP, with a wide linear detection range (0.001-300 µM), an ultra-low detection limit (0.0012 µM), and high sensitivity (0.23 mA µM⁻¹ cm⁻²). Additionally, the sensor demonstrates excellent reproducibility, long-term stability, and strong selectivity against potential interfering species. Furthermore, the real-sample analysis with the proposed sensor demonstrates accurate determination of CAP in milk, honey, eye drops, and fetal bovine serum (FBS), with desirable recovery. Collectively, these findings establish SSP derived nanostructured NiS films as a promising material platform for next-generation flexible electrochemical sensors for antibiotic detection.