Plasmonics Enhanced Spectroscopic and Electrochemical Analysis

Abstract

The localized surface plasmon resonance (LSPR) arises from the collective oscillation of conduction electrons of metal nanostructures which can be used to monitor recognition events of biomolecules at single nanoparticles1. The enhanced electric field around the nanostructures due to LSPR will significantly enhance the Raman scattering, fluorescence and IR spectra, which enable the realization of single molecule detection. In addition, the LSPR will excite high-energy electron-hole pair (referred to as “hot electrons” and “hot holes”) emerging on metal surface. The energetic charges will considerably affect the electrochemical reactions occurring at the nanoparticles. When the plasmonic metallic nanostructures are coupled to other substrates, for example, the semiconductor (i.e., TiO2, MoS2), the plasmon-excited hot electron-hole at nanoparticle surface can communicate with the conductance and valence bands of the semiconductors, resulting in variation in electro/photocatalytic activity. In this talk, we will start with the study on the possibility of LSPR for monitoring biomolecules and their recognition events at single nanoparticles.1 Then, we report the LSPR enhanced IR for biosensing.2 In the third part, we will show how the LSPR accelerates electrochemical reactions of electroactive biomolecules such as glucose on gold nanoparticles and hydrogen evolution reaction at molybdenum disulphide nanosheets.3 Based on the plasmonics accelerated electrochemical reactions (PAER), high sensitive electrochemical biosensors for detection of glucose and other electroactive biomolecules have been constructed. 1. (a) Y. Zhao, et al. Anal. Chem. 2013, 85: 1053; (b) B. Jin, et al. Langmuir, 2012, 28: 9460; (c) J.Y. Xu, et al. Chem. Comm. 2012, 48: 3052; (d) W.J. Bao, et al., Chem. Commun. 2014, 50: 7787; (e) Y. Zhao, et al. Chem. Commun. 2014, 50: 5480. 2. (a) J.Y. Xu, B. Jin, Y. Zhao, K. Wang, X.H. Xia, Chem. Commun. 2012, 48: 3052; 187. (b) B. Jin, G. X. Wang, D. Millo, P. Hildebrandt, X. H. Xia, J. Phys. Chem. C 2012, 116: 13038; (c) B. Jin, W. J. Bao, Z. Q. Wu, X. H. Xia, Langmuir 2012, 28: 9460; (d) J. Y. Xu, T. W. Chen, W. J. Bao, K. Wang, X. H. Xia, Langmuir 2012, 28: 17564; (e) W. J. Bao, Z. D. Yan, M. Wang, Y. Zhao, J. Li, K. Wang, X. H. Xia, Z. L. Wang, Chem. Commun. 2014, 50: 7787. 3. (a) Y. Shi, J. Wang, C. Wang, T.T. Zhai, W.J. Bao, J.J. Xu, X.H. Xia, H.Y. Chen, J. Am. Chem. Soc. 2015, 137: 7365; (b) 3. C. Wang, Y. Shi, X.G. Nie, Y. Zhou, J.J. Xu, X.H. Xia, H.Y. Chen, Science Advances, in revision.