Institute of Microanalytical System, Department of chemistry, Zhejiang University, Hangzhou 310058, China.
College of Civil Engineering and Architecture, Zhejiang university, Hangzhou 310058, China.
Talanta. 2014 Mar;120:135-40. doi: 10.1016/j.talanta.2013.12.007. Epub 2013 Dec 11.
Paper chips for immunoassay were patterned by screen printing of polydimethylsiloxane (PDMS) or wax pencil drawing. The methods for paper chip patterning are cheap, convenient, rapid and suitable for most laboratories. The whole time for patterning a paper chip is no more than 10 min. Visible immunoassay for the detection of bacteria (Escherichia coli ) has been realized using the paper chip, on which the antibody for capturing E. Coli was immobilized on the detection zones of the paper chip, while the detection antibody was labeled with gold nanoparticles (AuNPs) as a signal reporter. After an immunological reaction, the AuNPs bound on the paper chip can effectively catalyse the reduction of silver ions during the silver enhancing step, generating a visible result that can be read by naked eyes. The quantitative results can be acquired by scanning the silver stained paper chip with a commercial scanner/or digital camera. The density of E. coli in water samples can be measured after calibrating the gray value of silver stained spots with the logarithmic number of bacteria. The time and reagents consumed on the paper chip immunoassay is much smaller than those of conventional ELISA, while the sensitivity of the paper chip immunoassay is comparable to conventional ELISA. The technology proposed in this work displays a great potential in the in-situ analysis when daily monitoring of water quality are required.
采用丝网印刷或蜡笔绘图的方法对聚二甲基硅氧烷（PDMS）或蜡笔绘图的方法对纸芯片进行图案化。这些纸芯片图案化的方法成本低、操作方便、速度快，适合大多数实验室。整个图案化过程不超过 10 分钟。使用这种纸芯片实现了对细菌（大肠杆菌）的可见免疫分析，在检测区固定了用于捕获大肠杆菌的抗体，而检测抗体则标记有金纳米颗粒（AuNPs）作为信号报告。在免疫反应后，结合在纸芯片上的 AuNPs 可以在银增强步骤中有效地催化银离子的还原，产生可以通过肉眼读取的可见结果。通过用商用扫描仪/或数码相机扫描银染的纸芯片可以获得定量结果。通过用对数细菌数校准银染斑点的灰度值，可以测量水样中的大肠杆菌密度。与传统 ELISA 相比，纸芯片免疫分析所需的时间和试剂消耗要小得多，而纸芯片免疫分析的灵敏度与传统 ELISA 相当。当需要对水质进行日常监测时，本工作中提出的技术在原位分析方面显示出巨大的潜力。
