Positive Potential Operation of a Cathodic Electrogenerated Chemiluminescence Immunosensor Based on Luminol and Graphene for Cancer Biomarker Detection

Citations Over TimeTop 1% of 2011 papers

Abstract

In this work, we report a cathodic electrogenerated chemiluminescence (ECL) of luminol at a positive potential (ca. 0.05 V vs Ag/AgCl) with a strong light emission on the graphene-modified glass carbon electrode. The resulted graphene-modified electrode offers an excellent platform for high-performance biosensing applications. On the basis of the cathodic ECL signal of luminol on the graphene-modified electrode, an ECL sandwich immunosensor for sensitive detection of cancer biomarkers at low potential was developed with a multiple signal amplification strategy from functionalized graphene and gold nanorods multilabeled with glucose oxidase (GOx) and secondary antibody (Ab(2)). The functionalized graphene improved the electron transfer on the electrode interface and was employed to attach the primary antibody (Ab(1)) due to it large surface area. The gold nanorods were not only used as carriers of secondary antibody (Ab(2)) and GOx but also catalyzed the ECL reaction of luminol, which further amplified the ECL signal of luminol in the presence of glucose and oxygen. The as-proposed low-potential ECL immunosensor exhibited high sensitivity and specificity on the detection of prostate protein antigen (PSA), a biomarker of prostate cancer that was used as a model. A linear relationship between ECL signals and the concentrations of PSA was obtained in the range from 10 pg mL(-1) to 8 ng mL(-1). The detection limit of PSA was 8 pg mL(-1) (signal-to-noise ratio of 3). Moreover, the as-proposed low-potential ECL immunosensor exhibited excellent stability and reproducibility. The graphene-based ECL immunosensor accurately detected PSA concentration in 10 human serum samples from patients demonstrated by excellent correlations with standard chemiluminescence immunoassay. The results suggest that the as-proposed graphene ECL immunosensor will be promising in the point-of-care diagnostics application of clinical screening of cancer biomarkers.

Related Papers

• → What do we measure by a luminol-dependent chemiluminescence of phagocytes?(1989)99 cited
• → Enhancement and inhibition of luminol chemiluminescence by phenolic acids(1995)25 cited
• → Development of novel high-sensitivity chemiluminescence assay for luminol using thiourea derivatives(1999)9 cited
• → Variables in xanthine oxidase-initiated luminol chemiluminescence: Implications for chemiluminescence measurements in biological systems(1986)29 cited
• [Chemiluminescence in oxidation of luminol by chloramine derivatives of biogenic compounds].(2002)