Seedless one-spot synthesis of 3D and 2D Ag nanoflowers for multiple phase SERS-based molecule detection

Along with the fast development of synthesis technique of nanomaterial, surface-enhanced Raman scattering (SERS) has emerged as an attractive tool for molecule sensing in the field of food safety and environmental monitoring. In this paper, a novel seedless one-spot strategy was firstly used to synthesize a series of 3D and 2D Ag nanostructures by simply modulating the injection rate of Ag source under different temperature. Through monitoring their morphology evolution under various synthesis conditions, the formation mechanism of these nanostructures was investigated in detail. Especially, the as-prepared 3D hierarchical Ag nanoflowers exhibited superior SERS performance with an enhancement factor of 3.77 × 107 and a limit of detection (LOD) as low as 1.45 × 10-9 M for 2-naphthalenethiol. In addition, the practical SERS-based monitoring of para-aminothiophenol in gas and sodium saccharin in commercial red wine with ultra-low LOD of 7.08 × 10-6 M and 0.0018 mg/mL was subsequently realized using this Ag nanostructure, demonstrating their intriguing prospect in sensitive direct detection of food additives and environmental contaminant.