Preparation Of Adijustble SERS-active Substrates Using Polymer As A Bracket

Four poly-5-bromoisophthalic acid polyethylene glycol esters with different chain length were synthesized successfully using different molecular weight polyethylene glycol as raw materials. We have investigated characteristics of them by means of IR and 1HNMR spectroscopy.After four poly-5-bromoisophthalic acid polyethylene glycol esters with different chain length being adsorbed on nano silver, four spacing adjustable SERS substrates were got. And Raman spectra were used to investigate the activity of the four SERS substrates using R6G as probe molecules. Obvious difference was observed by comparing the surface-enhanced Raman scattering (SERS) spectra of the same concentration R6G probe molecules in different SERS substrate. The SERS signal of R6G adsorbed on silver nanoparticles,which were adjusted by poly esters synthesized by polyethylene glycol with 4000 molecular weight , is the strongest with excitation at 514.5 nm, While 1000 molecular weight with excitation at 632.8 nm.