Study Of Surface-enhanced Raman Spectroscopy Based On Optical Fiber Sensing/magnetic Nanocomposites

At present, there are several problems in the application of the biological/chemical sensors:1) bad environmental adaptability,2) limited application field,3) cannot detect universal target molecules,4) has many difficulties to detect the complex actual sample in the field. Spectral analysis combined with optical fiber can be used as an excellent candidate for the biological/chemical sensing. Combination of optical fiber technology and spectra analysis can achieve in situ, real-time, multi-channel, distributed and remote sensing in a complicated environment. Surface enhanced Raman spectroscopy has the advantages such as high sensitivity, good selectivity, non-destructive. The surface enhanced Raman technology based on optical fiber shows a potential application. On the other hand, although the SERS technology has the advantage of high sensitivity and selectivity, the analysis towards the complex samples in the real world can not be realized Hence, developing a new type of SERS substrate is an important research field. Metal nanoparticles, with its excellent enhance performance get the favor of many researchers, however, due to the easy coagulation greatly limited its application. Combination of the metal nanoparticles with the carrier for the SERS application is an effective way.Based on the above thinking, we pay attention to the SERS matrix and the multifunctional nanomaterial, design the SERS optical fiber sensor, and synthesized the magnetic nanocomposites for SERS detection of complex samples.1、Optical fiber SERS sensing: to explore the methods of preparation the activated hollow fiber with surface plasma resonance structure, the inside of the hollow fiber was assembled with gold nanoparticles. For the specific analysis, two kinds of target molecules (Atto-610labeled biotin and thiram) were detected. The results shows that the avidin-biotin system combined rapidly, after80min the saturated adsorption has been realized, and the minimum concentration was10ng/mL; The minimum limits of detection of the thiram was5×10-7mol/L.2、The preparation of graphene oxide/magnetic nanocomposites used as adsorbent which has the function of separation and enrichment to the low concentration of target molecules in the complex samples matrix.Using methylene blue (MB) as the target molecule, the adsorption ability of methylene blue was developed.,the minimum adsorption concentration of1×10-6mol/L.