The high sensitivity of the AuNPs/Si substrates was confirmed by the SERS spectra of malachite green detected with high quality at concentrations of . The SERS substrates can detect SERS spectra of tetracycline at low concentrations of around 1ppm. | VNU Journal of Science Mathematics Physics Vol. 36 No. 3 2020 66-73 Original Article Fabrication of SERS Substrates Using Au Nanoparticles Prepared by Laser Ablation in Distilled Water and Detection of Tetracycline at Low Concentrations Nguyen The Binh1 Nguyen Quang Dong2 1 Faculty of Physics VNU University of Science 334 Nguyen Trai Thanh Xuan Hanoi Vietnam 2 Department Basic Sciences Thai Nguyen University of Medicine and Pharmacy 248 Luong Ngoc Quyen Thai Nguyen Vietnam Received 14 February 2020 Revised 13 March 2020 Accepted 20 April 2020 Abstract We studied to produce SERS substrates using gold Au nanoparticles AuNPs prepared by pulse laser ablation PLA in water. The colloidal Au NPs with average size of 23nm were deposited on a silicon wafer to form AuNPs Si SERS substrate. Malachite green was chosen as a test analyte to examine the sensitivity of the SERS substrates. The SERS enhancement factor of the AuNPs Si was found to be about 106. The high sensitivity of the AuNPs Si substrates was confirmed by the SERS spectra of malachite green detected with high quality at concentrations of . The SERS substrates can detect SERS spectra of tetracycline at low concentrations of around 1ppm. Keywords Surface enhanced Raman scattering SERS pulse laser ablation enhancement factor EF SERS substrate. 1. Introduction Surface enhanced Raman scattering SERS was first discovered in 1974. Because of its huge sensitivity in spectroscopy the investigations of SERS and its applications have developed ceaselessly. The electromagnetic EM enhancement mechanism of SERS was based on the amplification of the incoming and scattered radiation the by the excitation of localized surface plasmon resonances LSPRs involving plasmonic nanostructures 1-5 . Gold Au silver Ag are often used as the plasmonic materials because they have LSPRs that cover most of the visible and near infrared wavelength range where most Raman measurements occur 6 7 . ____ Corresponding author. Email address
