Browsing by Author "Cai, Xinxia"

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    Low sample volume origami-paper-based graphene-modified aptasensors for label-free electrochemical detection of cancer biomarker-EGFR
    (Nature Publishing Group, 2020-05-18) Wang, Yang; Sun, Shuai; Luo, Jinping; Xiong, Ying; Ming, Tao; Liu, Juntao; Ma, Yuanyuan; Yan, Shi; Yang, Yue; Yang, Zhugen; Reboud, Julien; Yin, Huabing; Cooper, Jonathan M.; Cai, Xinxia
    In this work, an electrochemical paper-based aptasensor was fabricated for label-free and ultrasensitive detection of epidermal growth factor receptor (EGFR) by employing anti-EGFR aptamers as the bio-recognition element. The device used the concept of paper-folding, or origami, to serve as a valve between sample introduction and detection, so reducing sampling volumes and improving operation convenience. Amino-functionalized graphene (NH2-GO)/thionine (THI)/gold particle (AuNP) nanocomposites were used to modify the working electrode not only to generate the electrochemical signals, but also to provide an environment conducive to aptamer immobilization. Electrochemical characterization revealed that the formation of an insulating aptamer–antigen immunocomplex would hinder electron transfer from the sample medium to the working electrode, thus resulting in a lower signal. The experimental results showed that the proposed aptasensor exhibited a linear range from 0.05 to 200 ngmL−1 (R2 = 0.989) and a detection limit of 5 pgmL−1 for EGFR. The analytical reliability of the proposed paper-based aptasensor was further investigated by analyzing serum samples, showing good agreement with the gold-standard enzyme-linked immunosorbent assay
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    Paper-based microfluidic aptasensors
    (Elsevier, 2020-10-04) Ming, Tao; Luo, Jinping; Liu, Juntao; Sun, Shuai; Xing, Yu; Wang, Hao; Xiao, Guihua; Deng, Yu; Cheng, Yan; Yang, Zhugen; Jin, Hongyan; Cai, Xinxia
    For in-situ disease markers detection, point-of-care (POC) diagnosis has great advantages in speed and cost compared with traditional techniques. The rapid diagnosis, prognosis, and surveillance of diseases can significantly reduce disease-related mortality and trauma. Therefore, increasing attention has been paid to the POC diagnosis devices due to their excellent diagnosis speed and portability. Over the past ten years, paper-based microfluidic aptasensors have emerged as a class of critical POC diagnosis devices and various aptasensors have been proposed to detect various disease markers. However, most aptasensors need further improvement before they can actually enter the market and be widely used. There is thus an urgent need to sort out the key points of preparing the aptasensors and the direction that needs to be invested in. This review summarizes the representative articles in the development of paper-based microfluidic aptasensors. These works can be divided into paper-based optical aptasensors and paper-based electrochemical aptasensors according to their output signals. Significant focus is applied to these works according to the following three parts: (1) The ingenious design of device structure; (2) Application and synthesis of nanomaterial; (3) The detection principle of the proposed aptasensor. This is a detailed and comprehensive review of paper-based microfluidic aptasensors. The accomplishments and shortcomings of the current aptasensors are outlined, the development direction and the future prospective are given. It is hoped that the research in this review can provide a reference for further development of more advanced, more effective paper-based microfluidic aptasensors for POC disease markers diagnosis