A dynamically optical and highly stable pNIPAM @ Au NRs nanohybrid substrate for sensitive SERS detection of malachite green in fish fillet

A universal surface-enhanced Raman scattering (SERS) substrate with tuneable plasmonic behaviour and long term stability was synthesized and characterized, and the substrate was applied in the sensitive detection of fungicide malachite green (MG) in fish fillets. Temperature-responsive poly (N-isopropyl acrylamide) (pNIPAM) template and anisotropic Au nanorods (NRs) were synthesized to prepare pNIPAM @ Au NRs nano-hybrids with dynamically optical and SERS properties and high stability. Results showed that excitation wavelength-dependent SERS efficiency could be tailored by temperature-induced swelling and collapse of the nano-hybrids, thus anticipated optical and SERS properties of the composites could be obtained. Furthermore, the SERS performance, uniformity, long-term stability analysis, and MG in fish evaluation showed that the detection of MG in fish tissues was realized with a limit of detection of 1.58 x 10(-9) M (0.73 ng/g), and the pNIPAM @ Au NRs composites could serve as effective SERS substrates allowing trace level detection of contaminants for the food industry.