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Enhanced Conductivity of rGO/Ag NPs Composites for Electrochemical Immunoassay of Prostate-Specific Antigen

Lu Han, Cheng-Mei Liu, Shi-Lei Dong, Cai-Xia Du, Xiao-Yong Zhang, Lu-Hai Li, Yen Wei

Biosens Bioelectron. 2017 Jan 15;87:466-472.

PMID: 27591721

Abstract:

Electrode materials play a vital role in the development of electrochemical immunosensors (EIs), particularly of label-free EIs. In this study, composites containing reduced graphene oxide with silver nanoparticles (rGO/Ag NPs) were synthesized using binary reductants, i.e. hydrazine hydrate and sodium citrate. Due to the fact that graphene oxide (GO) was fully restored to rGO, and rGO stacking was effectively inhibited by insertion of small Ag NPs between the graphene sheets, the electrical conductivity of rGO/Ag NPs composites was significantly improved compared to rGO alone, with an enhancement factor of 346% at 40wt% of rGO. Moreover, the conducting path between rGO and Ag NPs formed because the structural defects in rGO were effectively repaired by decoration with Ag NPs. Subsequently, based on a screen-printed three-electrode system, a label-free EI for detecting prostate-specific antigen (PSA) was constructed using rGO/Ag NPs composites as a support material. The fabricated EIs demonstrated a wide linear response range (1.0-1000ng/ml), low detection limit (0.01ng/ml) and excellent specificity, reproducibility and stability. Thus, the proposed EIs based on rGO/Ag NPs composites can be easily extended for the ultrasensitive detection of different protein biomarkers.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP206986905 Silver citrate hydrate Silver citrate hydrate 206986-90-5 Price
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