Gold-aptamer modified dielectrode silica surface for hepatitis C virus core antigen sandwich assay

Abstract

Hepatitis C virus (HCV) cause both chronic and acute hepatitis, depends on the severity from mild to serious illness, leads a lifelong illness, such as liver cancer and liver cirrhosis. Chronic HCV is generally a silent infection for several years, until it damages the liver. Diagnosing HCV infection in a regular basis is mandatory and this research focused to quantify hepatitis C-core antigen (HCVcoreAg) on aptamer-gold modified dielectrode silica surface. Aptamer-biotin was immobilized on the electrode by using streptavidin-gold nanoparticle interaction, which enhance the number of aptamer attachment on interdigitated dielectrode (IDE). Further, aptamer-antibody sandwich assay was carried out to increase the analytical performance for HCVcoreAg detection and reached a limit of detection to 0.5 pg/mL on a linear increment range from 0.5 to 16 pg/mL with an acceptable regression coefficient [y = 1.0116×−1.372; R2 = 0.963]. In addition, blocking agent PEG-b-PAAc reduced the biofouling on IDE and control the increment of current responses in non-specific experiments, which helps to detect the HCVcoreAg in mixed biological samples without interferences. This sandwich assay detects the lower level of HCVcoreAg and diagnose HCV infection.