Study On The Drug Detection Of Noble Metals And TiO₂ Nanocomposites As SERS Substrates

Objective The detection of Enoxacin by Raman and surface enhanced Raman spectroscopy?SERS?was carried out using Au-TiO₂ nanocomposite as SERS active substrate,which was prepared by sol-hydrothermal and photocatalytic reduction methods.This not only improves the SERS performance of semiconductor TiO₂,but also expands the application range of semiconductor TiO₂ as the active substrate of SERS and establishes the drug detection based on SERS Technology.It provides a new method for drug detection.The interaction between enoxacin and the substrate was studied,and the effects of drug concentration and adsorption time on the interaction between drug molecule and substrate were investigated.Methods Au-TiO₂ nanocomposites were prepared by the method of sol-hydrothermal method and photocatalytic reduction,by changing the photocatalytic irradiation time and HAuCl4 concentration obtained the best SERS enhancement effect Au-TiO₂ nanocomposites,and characterized the nanoparticles.Au-TiO₂ nanocomposites used as the SERS active substrate for Enoxacin molecule detection,the effects of drug concentration and adsorption time on drugsubstrate-substrate interactions were investigated.Results The SERS performance of Au-TiO₂ nanocomposites was investigated by using drug intermediates mercaptobenzoic acid?4-MBA?as standard probe molecules.The experimental results show that Au-TiO₂ nanocomposites have a stronger SERS enhancement effect than TiO₂ substrates,and when the illumination time is 30 minutes and the HAuCl4 concentration is 1.5×10-9 M,the composite substrate had the best SERS enhancement effect,which is attributed to the charge-transfer-induced enhancement effect with the interaction/synergistic action of TiO₂ and Au.The intrinsic TiO₂-to-molecule CT and the additional CT assisted by LSPR of Au are together responsible for the considerable SERS enhancement of molecules on the Au-TiO₂ and the composite substrate has the characteristics of recycling.The qualitative analysis of enoxacin was carried out,when the adsorption time is 5 h,the composite substrate has the best SERS enhancement effect on Enoxacin,the minimum detection concentration of enoxacin can reach 1.0×10-6 M.The Raman signal of enoxacin enhancement is enhanced by TiO₂-to-molecule charge transfer.Conclusions The SERS performance of semiconductor TiO₂ is improved by the modification of noble metal,which extends the application range of semiconductor TiO₂ as SERS active substrate.Study on the drug detection of noble metal and TiO₂ nanocomposites as SERS active substrates.Au-TiO₂ nanocomposites were used as SERS active substrates to study the enoxacin.This not only expands the application of SERS technology and semiconductor TiO₂ as the active substrate of SERS,but also provides a new method for drug analysis.