One-step surfactant-free photoreduction synthesis of single-crystal silver triangular nanoprisms by surface modified chemically patterned ferroelectric crystals for SERS application

Abstract

Anisotropic metal nanoparticles with plasmonic and photocatalytic action exhibit significant applications for SERS detection and green transformation. Current synthetic approaches using multiple chemicals cause substantial resource consumption and surface chemical residues that hinder analyte adsorption and thus prevent efficient action. Herein, we present a green production process using surface modified ferroelectric templates to grow triangular Ag nanoprisms for surface enhanced Raman spectroscopy (SERS). Surface modification of ferroelectric templates with positively charged ions suppresses the Ag nucleation on template surface and enables the reaction-controlled process to promote anisotropic photoreduction for the growth of Ag nanoprisms. Under optimal experimental conditions, numerous Ag nanoprisms with the (111) plane can be photoreduced with sharp tips and edges and greatly strengthen the excited electric field for Raman signal enhancement. The synthesized Ag nanoprism array presents superior SERS performance, including enhancement factor of 3.78 × 108, limit of detection as low as 4.95 × 10-9 M, and Raman signal enhancement by 8.63 times. The practical application of Ag nanoprisms is effectively demonstrated by the SERS detection of antibiotics. The reaction control by utilization of surface-modified ferroelectric templates provides a promising prospect for the green synthesis of anisotropic metal nanomaterials and the technical development of green applications.