Poly(o-phenylenediamine)-carried nanogold particles as signal tags for sensitive electrochemical immunoassay of prolactin.

Huafeng Chen, Yuling Cui, Bing Zhang, Bingqian Liu, Guonan Chen, Dianping Tang

Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China.

Analytica chimica acta 2012 May 30

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A novel class of redox-active molecular tags, poly(o-phenylenediamine)-carried nanogold particles (GPPDs), was first synthesized and functionalized with horseradish peroxidase-anti-prolactin conjugates (HRP-anti-PRL). Thereafter, a specific sandwich-type electrochemical immunoassay was designed for determination of prolactin (PRL) by using GPPD-labeled HRP-anti-PRL conjugates as molecular tags on anti-PRL antibody-modified glassy carbon electrode. Compared with pure gold nanoparticles and poly(o-phenylenediamine) microspheres, the as-prepared GPPDs increased the surface coverage of the nanostructures, and enhanced the immobilization amount of biomolecules. Several labeling protocols compromising GPPD-labeled HRP-anti-PRL, nanogold particles-labeled HRP-anti-PRL and poly(o-phenylenediamine) microspheres-labeled HRP-anti-PRL, were investigated for detection of PRL, and improved analytical features were obtained with the GPPD-based strategy. With the GPPD labeling method, dependence of the electrochemical signals on the incubation time and pH of the assay solution were also studied. The strong attachment of HRP-anti-PRL to the GPPDs resulted in a good repeatability and intermediate reproducibility down to 9.8%. The dynamic concentration range spanned from 0.5 to 180 ng mL(-1) PRL with a detection limit of 0.1 ng mL(-1) at the 3S(blank) level. No significant differences at the 95% confidence level were encountered in the analysis of 10 spiked blank cattle serum samples between the developed immunoassay and enzyme-linked immunosorbent assay method for determination of PRL. Copyright © 2012 Elsevier B.V. All rights reserved.

Citation

Huafeng Chen, Yuling Cui, Bing Zhang, Bingqian Liu, Guonan Chen, Dianping Tang. Poly(o-phenylenediamine)-carried nanogold particles as signal tags for sensitive electrochemical immunoassay of prolactin. Analytica chimica acta. 2012 May 30;728:18-25