Preparation And Performance Of Hydrophobic Ag And Go SERS Substrates

Surface-enhanced Raman spectroscopy(SERS) substrate, based on plasma structure, shows a super sensitive and selective detection of unmarkers and molecular fingerprinting, but complicated preparation and high cost makes its SERS in practical applications and commercial applications a challenge. Now a platform can provide a small volume of detection in toxins detection and tracking on Criminology. Plasma structure can support a surface-enhanced Raman spectroscopy(SERS) for trace molecular detection. However, the detection for highly diluted sample with small size is still a challenge. This paper introduces two hydrophobic substrates. Hydrophobic substrates will not only make small sample test come true, but also have a good SERS effect.Hydrophobic substrate can increase the concentration of solution, due to the hydrophobic surface, so as to intensity enhancement of molecule Raman signal. And only covered on the surface of substrate, sample will be tested, simplify operation and solved the problem which the molecular hard to adsorb on hydrophilic substrate is difficult to be detected. In this paper, the first experiment is the preparation of hydrophobic Ag substrate adopted in situ reduction method, using the reducibility of flat polyaniline film. 30-minute reaction time can get uniform Ag film and make hydrophobic substrate through chemical modification available. By changing the conditions contained different reaction time and different modified reagents, it is easy to get the knowledge of surface property and SERS performance. In the process of modifying, we found that Soaking time for 3min, reagent modified solution for 12 mercapt an, can obtain good SERS substrates. On the molecular trace detection, the detection concentration of rhodamine B was as low as 10-9 M, while concentration of thiuram is at 10-8 M level, and had a great reproducibility.The second is hydrophobic GO SERS substrate acquired by hydrothermal approach, utilizing thiol acetallization, hydrogen bond and electrostatic effects between amine molecular and oxidation graphite. Finally, hydrophobic membrane is prepared by micro-vacuum filter. The effects of reactant ratio and modified reagent on surface property and SERS performance of substrate had been also discussed. When graphene oxide was 20 mg, and amine molecular was 0.02 mol, it was found that the substrate modified by hexadecylamine had the best SERS effect, on which condition the concentration of rhodamine B is 10-6 M. Hydrophobic SERS substrate can always ensure the analyte in a small area, preventing moleculars spreading anywhere.