Author:
S Srivatzen,BS Kavitha,Asokan Sundararajan
Abstract
Biomarker detection is pivotal in various fields, including healthcare, environmental monitoring, and biotechnology. This work introduces a versatile platform for biomarker detection by utilizing SU-8 negative photoresist coated etched Fiber Bragg Grating (eFBG) sensors in conjunction with antibody-antigen chemistry. The unique combination of FBG sensors and SU-8 coating offers several advantages, including enhanced sensitivity, selectivity, and versatility. In this study, we present the design and fabrication of SU-8 coated FBG sensors optimized for biomarker detection. The SU-8 coating not only provides a stable and biocompatible surface for immobilizing antibodies but also improves the sensor's response to specific antigen binding. As a proof of concept, the detection of concentration of standard antigen is demonstrated by functionalization of the SU-8 coated eFBG sensor with corresponding IgG antibody using EDC/NHS crosslinking chemistry. The reflected Bragg wavelength (lB) of the eFBG sensor is modulated by the added antigen concentration. The dynamic range of the sensor is from 8 pg/ml to 80 ng/ml with average sensitivity of 32.3 pm 10- 1 g-1 ml.