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

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.

Novel biomolecule lycopene-reduced graphene oxide-silver nanoparticle enhances apoptotic potential of trichostatin A in human ovarian cancer cells (SKOV3)

“…26 Graphene-based nanomaterials have been shown as excellent and suitable platforms for anchoring silver nanoparticles (AgNPs) for the production of graphene-Ag nanocomposites used as antimicrobial and anticancer agents. [27][28][29][30][31][32][33][34][35] Among several metallic nanoparticles, AgNPs are widely used in industry as well as biomedical applications due to their unique physical, chemical, and biological properties, particularly antibacterial, antiviral, antifungal, anti-inflammatory, anticancer, and antiangiogenic activities. Although AgNPs are presented as very attractive molecules in various therapeutic and industrial applications, they have a strong tendency to aggregate in aqueous solutions and are susceptible to aggregate into large particles owing to their high surface energy, resulting in deterioration of their unique chemical properties and loss of their antibacterial activities, which leads to a decrease in various biological activities.…”

New Horizons for Diagnostics and Therapeutic Applications of Graphene and Graphene Oxide

“…[ 80 , 81 ] Graphene functionalized ECL sensors have been widely used to detection biomarkers. Li et al [ 82 ] found that graphene modifi ed GCEs could exhibit strong cathodic ECL behavior in the presence of luminal at a positive potential (ca 0.05 V vs. Ag/AgCl). An ECL sandwich immunosensor for the sensitive detection of cancer biomarkers at low potentials was developed with a multiple signal amplifi cation strategy from chitosan-functionalized graphene (CHIT-GR) and gold nanorods multi-labeled with glucose oxidase and a secondary antibody (Ab2).…”

“…The proposed ECL immunosensor exhibited high sensitivity and specifi city for PSA with a detection range from 10 pg mL − 1 to 8 ng mL − 1 . [ 82 ] Graphene-QDs composites were also used as the ECL label in an advanced ECL immunosensor presented by Zhu and co-workers for the detection of human IgG protein. [ 83 ] Human telomerase is a ribonucleoprotein that adds the TTAGGG repeats on the telomeric ends of chromosomal DNA.…”

Electrochemical Immunosensor Based on the ZnO Nanorods Inside PDMS Channel for H7N9 Influenza Virus Detection

“…(photothermal deflection spectroscopy, PDS) [6], 화학발광법 (chemiluminescence) [7,8], 질량분석법(mass spectrometry) [9], 전 기화학 측정법(electrochemistry) [10][11][12] Step voltage 10 mV Fig. 7.…”