BaTiO3 SERS substrates for Dimethyl phthalate detection

Abstract

The surface spectroscopic technique, surface-enhanced Raman spectroscopy (SERS) is a powerful analytical tool for chemical and biological sensing applications. Noble metals like gold, silver, etc. have been most commonly used as SERS materials since their surface plasmon resonance can enhance the local electromagnetic field and amplify the SERS signals. However, the basic issue that has limited its use is the difficulty involved in producing uniform, sensitive, and reproducible efficient SERS substrates. Recently serious efforts have been focused on investigating the Raman activity of semiconductor nanomaterials with tunable chemical and physical properties, high selectivity, and sensitivity. In this work, nanosized phase pure Tetragonal structured Barium Titanate (BT) has been synthesized by modified sol–gel route. The bandgap of the perovskite BaTiO3 is 3.2 eV, determined from the diffused reflectance spectra. The optical phonon modes obtained from the Raman spectra again confirms the formation of the tetragonal Barium Titanate. To check the SERS activity of BT, Dimethyl phthalate (DMP) molecules were used as probe molecules. The BT substrates show great enhancement in the Raman spectra, many fingerprint Raman bands of Dimethyl phthalate were observed from the BT substrates. This enhanced SERS activity of BT can be explained based on the charge transfer resonance. The results demonstrate that noble metal-free Barium Titanate has great potential as a highly sensitive substrate for the detection of trace Dimethyl Phthalate.