The structural and textural characterization of the as-prepared SERS substrates were characterised by scanning electron microscope (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The SERS activity was studied by Raman scattering spetra of Malachite Green (MG) molecules in water at room temperature. The SERS results showed an enhancement (20 times) by coupling of MG molecules with a localized surface plasmon resonance of Ag NPs. The limit of detection of MG molecules was determined to be 10−7M. | Communications in Physics, Vol. 26, No. 3 (2016), pp. 261-268 DOI: PREPARATION OF SERS SUBSTRATES FOR THE DETECTION OF ORGANIC MOLECULES AT LOW CONCENTRATION TRAN THI KIM CHI1,† , NGUYEN THI LE2 , BUI THI THU HIEN1, DANG QUOC TRUNG1 AND NGUYEN QUANG LIEM1 1 Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam 2 Cao Bang Teachers’ Trainning College, De Tham, Cao Bang, Vietnam † E-mail: chittk@ Received 04 April 2016 Accepted for publication 10 August 2016 Abstract. We present the preparation of surface enhanced Raman spectroscopy (SERS) substrates by depositing silver nanoparticles (Ag NPs) onto the top of 1040 nm pores of porous silicon template produced by hydrofluoric acid (HF) etching. The influences of the anodizing current density on the pore size were systematically investigated. The structural and textural characterization of the as-prepared SERS substrates were characterised by scanning electron microscope (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The SERS activity was studied by Raman scattering spetra of Malachite Green (MG) molecules in water at room temperature. The SERS results showed an enhancement (20 times) by coupling of MG molecules with a localized surface plasmon resonance of Ag NPs. The limit of detection of MG molecules was determined to be 10−7 M. Keywords: SERS, chemical etching, Raman, malachite green. Classification numbers: , . I. INTRODUCTION Surface-Enhanced Raman Spectroscopy (SERS) is a surface-sensitive technique that enhances the Raman scattering signal of analyte molecules adsorbed on rough metal surfaces. This enhancement factor is often observed 104 –106 , and can be as high as 108 to 1014 for some systems [1–4]. Therefore, SERS is considered as an effective technique for chemical and bioanalytical detection [2, 3]. The enhanced Raman scattering can be explained in terms of .
