Tailored necklace-like Ag@ZIF-8 core/shell heterostructure nanowires for high-performance plasmonic SERS detection

Abstract

Aiming to the main challenges of high-performance SERS substrates involving the ultrasensitive and uniformity with large-area, herein, tailored necklace-like Ag@ZIF-8 core/shell heterostructure nanowires were synthesized by a facile two-step method. The well-defined heterostructure substrate exhibited a high active and sensitive SERS response toward crystal violet (CV) molecules. The detection CV signals can be as low as to 10−8 M. A remarkable average SERS enhancement factor (EF) up to 4.2 × 107 was achieved and it showed an excellent reproducibility with a relative standard deviation of 11.6%. And surprisingly, the Raman signals kept almost unchanged even during the experiment period of 60 days. Moreover, the heterostructure substrate as versatile SERS platform could be used to detect the insoluble trace analytes with a high EF of 1.9 × 107 for thiram, and 1.3 × 106 for 1,3,5-melamine. The high SERS performances of such heterostructure nanowires can be attributed to the enrichment effect of the porous ZIF-8 nanoparticles. This work might provide a facile strategy for construction of MOF-based nanostructures as potential SERS platform for molecular detection.