Gold modified screen printed carbon electrode (SPCE) with steptavidin-biotin system for detection of heart failure by using immunosensor

Abstract

Immunosensor for heart failure detection using the BNP (B type Natriuretic Peptide) biomarker was developed in this study. BNP can be identified with anti-BNP antibodies using immunosensor method electrochemically. Anti-BNP antibodies are immobilized on the SPCE surface with the biotin-streptavidin system. Modification of SPCE with gold can increase the detection limit in determining BNP concentration. This study aims to develop a BNP detecting immunosensor for the diagnosis of heart failure using gold-modified SPCE. The SPCE surface is characterized before and after modification with gold. Anti-BNP antibodies were immobilized on the surface of gold-modified SPCE with the biotin-streptavidin system and optimized antibody concentrations and incubation times were measured. BNPs with varied concentration variations were tested on immunosensors to determine their sensitivity and detection limits. SPCE surface characteristics before and after modification with gold can increase surface area and electroactive properties on the surface of the electrode. Better current signal response is generated at both primary and secondary antibody concenfrations of 5.0 and 1.0 μg/mL as well as the incubation time of secondary antibody and BNP antigen for 30 min. The developed immunoensensor showed a linear response at a BNP concentration of 10 to 100 fg/mL, with a detection limit of 34 fg/mL.