Paper-based Versatile SERS Chip with Smartphone-based Raman Analyzer for Point of Care Application

摘要： With the advanced development of the miniaturized Raman spectroscopy, surface enhanced Raman spectroscopy (SERS) has extended its applications into the field of Point of Care Testing (POCT) and demonstrated its great significance in virtue non-invasive property and capability of fingerprint identification. In the SERS-based analysis and/or sensing system, the preparation of low cost, high-performance SERS substrate is critically important. In this manuscript, vacuum filtration is utilized to fabricate the silver nanoparticles (AgNPs) embedded nylon filter membrane (ANFM) as flexible paper-based SERS chips. By characterizing the typical analytes with the miniaturized smartphone-based Raman analyzer, the proposed SERS chips have successfully demonstrated good sensitivity, repeatability and stability. The lowest concentration as detected can approach 1 pmol for Rhodamine 6G (RH6G) and 10 pmol for both crystal violet (CV) and malachite green (MG), respectively. With the help of microporous structure of the membrane, the ANFM based SERS chips can implement the separation of small molecules from complex mixture and can achieve “purified” SERS signals of targeted molecules. Besides, with the function of anti-friction resistance and flexibility, the ANFM can serve as SERS papers to pre-concentrate the contaminates by multiple swapping and further enhance the SERS signals for point of care analysis. Therefore, we demonstrate multi-functions of the flexible ANFM based SERS chips, which provides a promising solution for the POCT analysis with SERS technique on account of its flexibility and low fabrication cost.