A Novel Biosensor Based on LAPS for the Detection of IgG

Abstract

Immunoglobulin G (IgG) is one of the most important factors in diagnosing some diseases in clinic. A novel biosensor for dectection of IgG based on light-addressable potentiometric sensor (LAPS) was presented in this paper. The LAPS measurement system included the LAPS sensor, light source, the electrode and the electrochemical workstation. The LAPS sensor was fabricated by the method of the Layer-by-Layer Self-Assembly (LBL-SA). The IgG antibody modified onto the silicon wafer of LAPS to capture the corresponding antigen by the specific immune response which has an effect on the sensitive of LAPS to change the photocurrent. The laser diode (LD) light source of 890 nm wavelength was chose as illuminant to drive the LAPS to create the photocurrent. A FPGA was introduced to control the LD and generate a sine wave signal with the special frequency. Different concentration of IgG arranged 50-150μg/mL was detected by the LAPS system. A calibration curve that represented linear correlation between the bias voltage values and theconcentration of IgG was illustrated, and the linear correlation coefficient was 0.9943. This new biosensor can be very useful for detection of IgG based on the LAPS principle.