Open Access Nano Express

A Novel Quantum Dots–Based Point of Care Test for Syphilis

Hao Yang1, Ding Li2, Rong He1, Qin Guo1, Kan Wang1, Xueqing Zhang1, Peng Huang1 and Daxiang Cui1*

Author Affiliations

1 Department of Bio-Nano Science and Engineering, Key Laboratory for Thin Film and Microfabrication Technology of Ministry of Education, National Key Laboratory of Micro/Nano Fabrication Technology, Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, 200240, Shanghai, People’s Republic of China

2 Center of Biological Diagnosis and Therapy, No. 261 Hospital of PLA, 100094, Beijing, China

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Nanoscale Research Letters 2010, 5:875-881  doi:10.1007/s11671-010-9578-1

Published: 23 March 2010

Abstract

One-step lateral flow test is recommended as the first line screening of syphilis for primary healthcare settings in developing countries. However, it generally shows low sensitivity. We describe here the development of a novel fluorescent POC (Point Of Care) test method to be used for screening for syphilis. The method was designed to combine the rapidness of lateral flow test and sensitiveness of fluorescent method. 50 syphilis-positive specimens and 50 healthy specimens conformed by Treponema pallidum particle agglutination (TPPA) were tested with Quantum Dot-labeled and colloidal gold-labeled lateral flow test strips, respectively. The results showed that both sensitivity and specificity of the quantum dots–based method reached up to 100% (95% confidence interval [CI], 91–100%), while those of the colloidal gold-based method were 82% (95% CI, 68–91%) and 100% (95% CI, 91–100%), respectively. In addition, the naked-eye detection limit of quantum dot–based method could achieve 2 ng/ml of anti-TP47 polyclonal antibodies purified by affinity chromatography with TP47 antigen, which was tenfold higher than that of colloidal gold–based method. In conclusion, the quantum dots were found to be suitable for labels of lateral flow test strip. Its ease of use, sensitiveness and low cost make it well-suited for population-based on-the-site syphilis screening.

Keywords:
Syphilis; Lateral flow; Diagnostics; Quantum dots; Nanomaterial