Facile synthesis of novel Ni-BDC-NH2/Au NPs SERS substrates with synergistic enhancement effects for high-performance detection

Substrate materials with high sensitivity and good reproducibility are highly desirable for the practical applications of surface-enhanced Raman scattering (SERS) techniques. In this study, a novel Ni-based metal-organic frameworks loaded gold nanoparticles (Ni-BDC-NH2/Au NPs) SERS substrate was successfully synthesized via electrostatic self-assembly method. The enhancement of the SERS signal is achieved owing to the synergy between chemical enhancement (CM) effect of Ni-BDC-NH2 and the electromagnetic enhancement (EM) of Au NPs, and the enriching of the analyte near the SERS “hot spots” through the strong adsorption capacity of the Ni-BDC-NH2. The Ni-BDC-NH2/Au NPs exhibited a high enhancement factor (EF) of 1.10×107 and a low detection limit of 5×10-9 mol/L. Besides, the substrate material showed exceptional stability up to 45 days at room temperature. The Ni-BDC-NH2/Au NPs was used to detect methylene blue (MB) that displayed a wide linearity (5×10-7-5×10-5 mol/L) and high recoveries (86.82-104.46%). These indicate that the Ni-BDC-NH2/Au NPs hybrid substrate has great potential for the detection of environmental pollution in practical applications.