a College of Sciences, Yanshan University, Qinhuangdao 066004, China; b School of Science and State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China; c Analytical and Testing Center, Beijing Normal University, Beijing 100875, China
Abstract A large-scale Si nanowire array (SiNWA) is fabricated with gold (Au) nanoparticles by simple metal-assisted chemical etching and metal reduction processes. The three-dimensional nanostructured Au/SiNWA is evaluated as an active substrate for surface-enhanced Raman scattering (SERS). The results show that the detection limit for rhodamine 6G is as low as 10-7 M, and the Raman enhancement factor is as large as 105 with a relative standard deviation of less than 25%. After the calibration of the Raman peak intensities of rhodamine 6G and thiram, organic molecules could be quantitatively detected. These results indicate that Au/SiNWA is a promising SERS-active substrate for the detection of biomolecules present in low concentrations. Our findings are an important advance in SERS substrates to allow fast and quantitative detection of trace organic contaminants.
Fund: Project supported by the National Natural Science Foundation of China (Grant No. 11104008), the Beijing Natural Science Foundation, China (Grant No. 4142040), the Doctoral Fund of the Ministry of Education of China (Grant No. 20090010120014), the Beijing Higher Education Young Elite Teacher Project, and the Technology Research and Development Program of Qinhuangdao City, China (Grant Nos. 201001A034 and 2012021A056).
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