Preparation Of Porous Silicon/Silver Structure Composite Particles With High SERS Performance And Its Application In Malachite Green Detection

Malachite green(MG)is a synthetic organic compound with good bactericidal effect.However,it is illegally abused in the processing of agricultural and sideline products,which leads to excessive drug residues in agricultural and sideline products,posing an important threat to food safety.Therefore,there is an urgent need for a rapid detection technology for drug residues in agricultural products.Currently,Surface enhanced Raman scattering(SERS)has been widely concerned in the fields of biological and food detection due to its high stability,sensitivity,and unique molecular recognition ability.The SERS active substrate is the foundation and guarantee for achieving high SERS detection,while metal-coupled solid-state active substrates have become one of the key bottlenecks for improving SERS performance.Therefore,the preparation of metal coupling systems with stable performance and high sensitivity is crucial.Aiming at the issues of low sensitivity and complex process of traditional MG detection,this paper designed and synthesized a metal coupling system active substrate with high SERS performance,which realized the fast and sensitive detection of MG..The main work content and innovative points of the paper are as follows:(1)A method is proposed to prepare porous silicon/dendritic silver structured irregular composite particle substrates using electrochemical corrosion,electrochemical stripping,and ultrasonic vibration in a step-by-step manner.The mechanism for the preparation of composite particle substrates using hydrofluoric acid(HF)and dimethylformamide(DMF)reagents was explored,revealing the factors affecting the formation of porous silicon and the deposition of silver structures.(2)The SERS performance of porous silicon/silver composite particle substrate was studied,and the high SERS activity of the composite particle substrate was experimentally verified.The Control variates was used to explore the influence of the concentration of silver nitrate solution in the electrolyte on the preparation of dendritic silver structures on the surface of active SERS substrates.At the same time,the effect of silver nitrate solution concentration on the SERS performance of porous silicon/silver composite particle substrate was studied.The SERS performance of the coupling system was verified using R6 G,and the optimal concentration value of silver nitrate solution was determined.The results show that the effect of silver nitrate solution concentration on SERS intensity shows a trend of increasing first and then decreasing;the composite particle substrate has high SERS performance and high detection sensitivity;finally,the substrate has good Raman enhanced reproducibility,stability,and uniformity,making it a stable and reliable high SERS performance substrate.(3)Based on this particle substrate,a study was conducted on the detection of low concentration residues of malachite green(MG)in fish meat.The SERS detection results of malachite green indicate that the composite particle substrate has good sensitivity in detecting malachite green aqueous solution,and linear regression is reliable;the characteristic peak of MG in the recovered fish spiked samples is detected,which proves the feasibility and effectiveness of the composite particle substrate in the field of food safety detection.This article proposes a step-by-step preparation method for porous silicon/dendritic silver structured irregular composite particle SERS substrate based on electrochemical technology,and conducts research on SERS detection application.The preparation mechanism,method,and morphology characterization of porous silicon/silver composite particle substrates were systematically explained from both theoretical and experimental perspectives.The influence in element distribution and microscopic morphology on SERS performance were systematically explored,revealing the mechanism and method of SERS enhancement performance of composite particle substrates.The research results provide a theoretical basis for the design and manufacturing of new SERS biosensors,and a new method for rapid detection of low concentration malachite green residues in agricultural products.