Surface Enhanced Vibration Spectrum Application In Environmental Analysis Research

In recent years, the pesticide residues and pathogenic bacteria in the environment was closely related to the people’s quality of life, the study of priority pollutants in the environment has become an advanced research hotspot. The attention of whole society to the environmental pollutants made demands for detection technology, so how to quickly and accurately monitor was particularly important for the pollutants existed in environmental. Surface enhancement vibration spectrum (SEVS) owned high sensitivity, and it also could provided fingerprint information data, the most important thing is that, along with the production of portable instrument, our prepared substrate could achieve the goal of onsite and rapidly detection. In conclusion, this technology had become a powerful means to detected priority pollutants in the environment.This paper was based on surface enhanced vibration spectrum technology, we prepared a series of nanomaterials with the method of chemical synthesis in liquid, and then the concentration of gold nanoparticles of different particle size were calculated. First of all, we utilized thiol compounds as the probe molecules, and optimized the conditions of enhancement effect, then the optimal enhancement conditions were determined, including the following conditions:different three-dimensional porous material, immobilization pattern, different concentration of nanoparticles, different kinds of nanomaterials, different size of gold nanoparticles. Eventually the preparation of three-dimensional porous SEVS substrate was optimized:three-dimensional porous filter paper and nickel foam is a good choice as carrier material, the two way of physical adsorption and adhesive assembly is a good choice for gold nanorod and gold nanoparticles (46 nm) immobilized on the carrier.Then, we prepared the SEVS substrate with optimal conditions, and pesticides, polycyclic aromatic hydrocarbons, and pathogenic E.coli were tested by prepared SEVS substrate. On the one hand, we utilized gold nanoparticles (46 nm) attached to the carrier of filter paper by the way of physical adsorption and adhesive. We also discussed the SEVS substrate of response to the environment polycyclic aromatic hydrocarbons and pesticides. Finally, we find that the prepared substrate has excellent response to phoxim in the environment, and low detection limit of phoxim is 4 μg. On the other hand, nanoparticles was loaded on nickel foam material by the use of the dopamine. At the same time, the substrate was applied to the detection of E.coli by the infrared transmission mode, and the study found that the substrate had a very good capture efficiency for E.coli in the water and the sensitivity reached up to 4.54×103 cell/mL. Moreover, gold nanorods was fixed to the carrier filter paper by the way of physical adsorption. In total, the process preparation of substrate is simple, the detection limit was as low as 5.18×104 cell/mL with the substrate by the type of infrared reflection when detecting E.coli in water. Different with traditional analysis methods, without complex pretreatment process and combining SEVS substrate with portable infrared spectrometer, the analysis method could received more extensive application in the field of environmental monitoring.