Fabrication of Au@MIL-101 (Fe) nanocomposite as highly sensitive SERS substrate for trace detection of sulfapyridine

This paper reports a two-step method for preparing a metal-organic framework (MOF) MIL-101 (Fe) based substrate with high sensitivity and stability for surface-enhanced Raman scattering (SERS) analysis. Firstly, MIL-101 (Fe) nanoparticles were synthesized using a traditional solvothermal method. Next, gold nanoparticles (AuNPs) were produced through a reduction method, and the AuNPs/MIL-101 (Fe) composite substrate was created by combining MIL-101 (Fe) with AuNPs. The adsorption capacity of the substrate and its SERS activity after multiple cleaning were tested. Using Rhodamine 6 G (R6G) as the probe molecule, the substrate's detection capability reached 10-8 M, with a relative standard deviation (RSD) of approximately 13.15%, indicating excellent SERS performance and uniformity. The ideal detection capability for sulfapyridine using the composite matrix can be as low as 10-6 M. This proposed substrate is convenient and efficient, holding great potential for the rapid and sensitive detection of antibiotic residues and other environmental pollutants.