Graphene-based immunosensor for electrochemical quantification of phosphorylated p53 (S15)

Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, PR China.
Analytica chimica acta (Impact Factor: 4.51). 08/2011; 699(1):44-8. DOI: 10.1016/j.aca.2011.05.010
Source: PubMed


We reported a graphene-based immunosensor for electrochemical quantification of phosphorylated p53 on serine 15 (phospho-p53(15)), a potential biomarker of gamma-radiation exposure. The principle is based on sandwich immunoassay and the resulting immunocomplex is formed among phospho-p53 capture antibody, phospho-p53(15) antigen, biotinylated phospho-p53(15) detection antibody and horseradish peroxidase (HRP)-labeled streptavidin. The introduced HRP results in an electrocatalytic response to reduction of hydrogen peroxide in the presence of thionine. Graphene served as sensor platform not only promotes electron transfer, but also increases the surface area to introduce a large amount of capture antibody, thus increasing the detection sensitivity. The experimental conditions including blocking agent, immunoreaction time and substrate concentration have been optimized. Under the optimum conditions, the increase of response current is proportional to the phospho-p53(15) concentration in the range of 0.2-10 ng mL(-1), with the detection limit of 0.1 ng mL(-1). The developed immunosensor exhibits acceptable stability and reproducibility and the assay results for phospho-p53(15) are in good correlation with the known values. This easily fabricated immunosensor provides a new promising tool for analysis of phospho-p53(15) and other phosphorylated proteins.

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Available from: Dan Du, Oct 05, 2015
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    • "TH has been used to induce photodynamic inactivation of bladder cancer cells, Escherichia coli, and Saccharomyces cerevisiae [17]. The biological activity of TH has also been employed in graphene-based inmuno sensors [18]. In addition to its favorable applications, TH possess mutagenic activity in eukaryotic cells, demonstrating its potential cytotoxic and genotoxic activity in prokaryotic cells and photo induced mutagenic action upon binding to DNA [19] [20] [21]. "
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    • "As a result, many researchers have made efforts to increase the solubility of GS. Thus, the water-soluble polymers, such as polyvinylpyrrolidone [16], polypyrrole (PPy) [17], chitosan [18,19] and Nafion [20,21] were used as dispersants to prepare homogeneous GS solutions, while the introduction of these polymers could promote electron transfer well. Significantly, some scientists have found that graphene-based composite materials, such as, gold nanoparticles and 1-pyrenebutyric acid-functionalized grapheme [22], graphene/polyaniline nanocomposite [23], AuNPs/PDDA-G [24], AuNPs decorated graphene (AuNPs-GS) [25] and MWCNTs-GS composites [26] are a useful approach. "
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