Evaluation of Surface Second Harmonic Generation SSHG for Detection of Antibody-Antigen Interactions

Abstract

Surface Second Harmonic Generation (SSHG) is an optical non-linear analytical technique that has been applied to various biological and non-biological systems. Its application to biological systems has been limited to imaging and studies of molecular structures. However, its potential as a label-free method to detect bio-molecular interactions was not thoroughly investigated. This study explored, probed and evaluated the potential of SSHG as a viable biosensing technique. The present study is undertaken to investigate the application of SSHG technique as a viable biosensing technique. This work probed immunoassays of a protein antigen (Ag), namely bovine serum albumin (BSA). The Ag-Ab interactions were detected using (ELISA). BSA was selected to represent natural non-glycoslated proteins. The optimization processes were trial and error experimentation with various Ag and its Primary Antibody (PAb) concentrations. Application of SSHG spectroscopy on these immunoassays and comparing them with the reference method, i.e. ELISA.