Open Access Nano Commentary

A CCD-based reader combined with CdS quantum dot-labeled lateral flow strips for ultrasensitive quantitative detection of CagA

Chen Gui1, Kan Wang1*, Chao Li1, Xuan Dai1 and Daxiang Cui12*

Author Affiliations

1 Institute of Nano Biomedicine and Engineering, Key Laboratory for Thin Film and Microfabrication of Ministry of Education, Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, 800Dongchuan Road, Shanghai 200240, People's Republic of China

2 Research Institute of Translation Medicine, Shanghai Jiao Tong University, 800Dongchuan Road, Shanghai 200240, People's Republic of China

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Nanoscale Research Letters 2014, 9:57  doi:10.1186/1556-276X-9-57

Published: 4 February 2014

Abstract

Immunochromatographic assays are widely used to detect many analytes. CagA is proved to be associated closely with initiation of gastric carcinoma. Here, we reported that a charge-coupled device (CCD)-based test strip reader combined with CdS quantum dot-labeled lateral flow strips for quantitative detection of CagA was developed, which used 365-nm ultraviolet LED as the excitation light source, and captured the test strip images through an acquisition module. Then, the captured image was transferred to the computer and was processed by a software system. A revised weighted threshold histogram equalization (WTHE) image processing algorithm was applied to analyze the result. CdS quantum dot-labeled lateral flow strips for detection of CagA were prepared. One hundred sera samples from clinical patients with gastric cancer and healthy people were prepared for detection, which demonstrated that the device could realize rapid, stable, and point-of-care detection, with a sensitivity of 20 pg/mL.

Keywords:
Test strip reader; CCD; Revised WTHE algorithm; CdS quantum dots; CagA