A simple and convenient preparation of flexible paper-Ag NPs substrate for surface enhanced Raman spectroscopy

Abstract

In recent years, flexible SERS substrates based on cellulosic materials have been widely investigated. In this study, paper was dissolved and dispersed in an alkaline solution, and Ag NPs were synthesised in situ on cleaned paper scraps, which were dried to form a complete paper SERS substrate. The whole preparation process is simple, the preparation time is short, and the Ag NPs are uniformly distributed inside and outside the paper, which can be arbitrarily cut and extracted by wiping the analyte surface, which is convenient for liquid sample detection. Most importantly, the substrate overcomes the problem of paper dissolution and damage due to immersion. The detection of 10 -7 M R6G was achieved with enhancement factor of 1.95 × 10 5 . The Raman activity was still present after 60 days of refrigerated storage. The reproducibility was good (RSD = 9.5 %). And now the substrate has been successfully used for the detection of ciprofloxacin in water, with the detection limits of 2.2 × 10 -4 M.