Theranostics 2016; 6(1):54-64. doi:10.7150/thno.13159 This issue

Research Paper

A Wash-Free Homogeneous Colorimetric Immunoassay Method

Huiqiao Liu1,#, Pengfei Rong2,#, Hongwei Jia3,#, Jie Yang1, Bo Dong1, Qiong Dong2, Cejun Yang2, Pengzhi Hu2, Wei Wang2, Haitao Liu3, Dingbin Liu1,✉

1. College of Chemistry, Research Center for Analytical Sciences, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Molecular Recognition and Biosensing, and Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, 94 Weijin Road, Tianjin 300071, China
2. Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
3. Key Laboratory of Optical Information Science and Technology, Ministry of Education, Institute of Modern Optics, Nankai University, Tianjin 300071, China
# H.L., P.R., and H. J. contributed equally to this work.

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) License. See for full terms and conditions.
Liu H, Rong P, Jia H, Yang J, Dong B, Dong Q, Yang C, Hu P, Wang W, Liu H, Liu D. A Wash-Free Homogeneous Colorimetric Immunoassay Method. Theranostics 2016; 6(1):54-64. doi:10.7150/thno.13159. Available from

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Graphic abstract

Rapid and convenient biosensing platforms could be beneficial to timely diagnosis and treatment of diseases in virtually any care settings. Sandwich immunoassays, the most commonly used methods for protein detection, often rely on expensive tags such as enzyme and tedious wash and incubation procedures operated by skilled labor. In this report, we revolutionized traditional sandwich immunoassays by providing a wash-free homogeneous colorimetric immunoassay method without requirement of any separation steps. The proposed strategy was realized by controlling the growth of gold nanoparticles (AuNPs) to mediate the interparticle spacing in the protein-AuNP oligomers. We have demonstrated the successful in vitro detection of cancer biomarker in serum samples from patients with high clinical sensitivity and specificity.

Keywords: colorimetric immunoassay, gold nanoparticles, clinical diagnostics