A Colorimetric Enzyme-Linked Immunosorbent Assay with CuO Nanoparticles as Signal Labels Based on the Growth of Gold Nanoparticles In Situ

Dehua Deng; Yuanqiang Hao; Jiajia Xue; Xiuhua Liu; Xinyue Xu; Lin Liu

doi:10.3390/nano9010004

A Colorimetric Enzyme-Linked Immunosorbent Assay with CuO Nanoparticles as Signal Labels Based on the Growth of Gold Nanoparticles In Situ

Nanomaterials (Basel). 2018 Dec 20;9(1):4. doi: 10.3390/nano9010004.

Authors

Dehua Deng^{1

2}, Yuanqiang Hao³, Jiajia Xue⁴, Xiuhua Liu⁵, Xinyue Xu⁶, Lin Liu^{7

8}

Affiliations

¹ College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475001, Henan, China. ddh@aynu.edu.cn.
² Henan Province of Key Laboratory of New Optoelectronic Functional Materials, Anyang Normal University, Anyang 455000, Henan, China. ddh@aynu.edu.cn.
³ Henan Key Laboratory of Biomolecular Recognition and Sensing, College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, Henan, China. haoyuanqiang@aliyun.com.
⁴ Henan Province of Key Laboratory of New Optoelectronic Functional Materials, Anyang Normal University, Anyang 455000, Henan, China. xjj18239553249@aliyun.com.
⁵ College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475001, Henan, China. liuxiuhua@henu.edu.cn.
⁶ Henan Province of Key Laboratory of New Optoelectronic Functional Materials, Anyang Normal University, Anyang 455000, Henan, China. xinyuexu@aliyun.com.
⁷ Henan Key Laboratory of Biomolecular Recognition and Sensing, College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, Henan, China. liulin@aynu.edu.cn.
⁸ Henan Province of Key Laboratory of New Optoelectronic Functional Materials, Anyang Normal University, Anyang 455000, Henan, China. liulin@aynu.edu.cn.

Abstract

A colorimetric immunoassay has been reported for prostate-specific antigen (PSA) detection with CuO nanoparticles (CuO NPs) as signal labels. The method is based on Cu²⁺-catalyzed oxidation of ascorbic acid (AA) by O₂ to depress the formation of colored gold nanoparticles (AuNPs). Specifically, HAuCl₄ can be reduced by AA to produce AuNPs in situ. In the presence of target, CuO NPs-labeled antibodies were captured via the sandwich-type immunoreaction. After dissolving CuO nanoparticles with acid, the released Cu²⁺ catalyzed the oxidation of AA by O₂, thus depressing the generation of AuNPs. To demonstrate the accuracy of the colorimetric assay, the released Cu²⁺ was further determined by a fluorescence probe. The colorimetric immunoassay shows a linear relationship for PSA detection in the range of 0.1~10 ng/mL. The detection limit of 0.05 ng/mL is comparable to that obtained by other CuO NPs-based methods. The high throughput, simplicity, and sensitivity of the proposed colorimetric immunoassay exhibited good applicability for assays of serum samples.

Keywords: CuO nanoparticles; ascorbic acid; colorimetric immunoassay; fluorescence immunoassay; gold nanoparticles.