Controllable Preparation And Application In SERS Of Multiple Tips Nanochestnut Arrays

Surface-enhanced Raman spectroscopy?SERS?enables the rapid identification and detection of trace pesticide residues present in trace amounts in the environment and foods.Herein,a facile approach to fabricate unique gold nanochestnuts?GNCs?as ultra-sensitive SERS substrate for detecting trace pesticide residues has been developed based on anodic aluminum oxide?AAO?templates.Gold GNCs are synthesized through galvanic replacement of silver on the top of nickel nanorod arrays.The as-prepared GNCs have well controlled structural parameters and importantly with unique anisotropic morphologies,benefiting to the enhancement in SERS performance.As a result,R6 G can be efficiently detected with GNCs as SERS substrate even with the concentration of only 10^-1212 M,and the Raman enhancement factor reaches up to 10¹22 at this concentration.Further SERS measurement of thiram indicates a remarkable SERS-active sensitivity of the as-prepared GNCs with a detection limit of thiram up to 10^-14M and exhibits high signal to noise ratio?SNR?.