Construction of Ag nanoflowers@ZIF-8 core-shell nanocomposite for sensitive SERS detection of hazardous substance in river water

Abstract

The presence of hazardous substance in river water poses a severe threat to both the ecological environment and human health. Therefore, designing and preparing highly sensitive SERS platform for monitoring the hazardous substance is of great significance. Herein, the Ag nanoflowers (NFs)@ZIF-8 core-shell nanocomposite was synthesized and utilized as SERS substrate. Using crystal violet as model molecule, this substrate achieved a detection limit of 10−10 M and superior uniformity with relative standard deviation of less than 15 %, and the enhancement factor (EF) for crystal violet was calculated about 4.37×106. Besides, the SERS signal only showed a slight attenuation after 3 months storage. As a demonstration, the SERS platform achieved sensitive detection of two hazardous substances thiram and methylene blue with detection limits of 10−7 M and 10−8 M. And the recoveries of SERS detection for thiram and methylene blue in river water were between 70 % and 182 %. The electromagnetic enhancement provided by Ag NFs and the enriching effect of ZIF-8 shell collectively contribute to the excellent performance of the Ag NFs@ZIF-8 SERS platform. This work delivers a promising strategy for constructing hybrid SERS platform for highly sensitive detection.