纸基微流控芯片的构建及在亚硝酸盐检测中的应用

Preparation of Paper-Based Microfluidic Chips and Its Application in Nitrite Detection

基于造纸过程中的表面施胶工艺,通过简单、高效的喷墨打印技术在纸张表面成功构建亲水性微流道。以纸张表面润湿性及液体在微流道内的扩散性为评价标准,研究了表面施胶剂配比、压光处理等因素对流体在微流道内的扩散行为的影响,研究结果表明:采用配比(m_(表面施胶淀粉)/m_(AKD))为7∶3的表面施胶剂对纸张进行疏水改性,在压强为2 MPa、辊速为3.5 m/min的条件下进行表面压光处理后构建的微流道展现出优异的限液性能,液体可以在亲水通道内实现完整地定向扩散,同时解决了液体的z向扩散问题。最后,采用文中构建的纸基芯片实现了对亚硝酸盐的定量检测,溶液质量浓度与芯片表面色差值之间呈良好的相关性,二者的曲线拟合方程为y=1.799+8.745 x^(0.453),相关系数达0.9935。

Based on the surface sizing process in the papermaking field and simple inkjet printing technology,a hydrophilic microfluidic channel was constructed on the surface of the paper.Taking the wettability of the paper surface and the diffusion property of the liquid in the channel as the evaluation criteria,the paper studied the effect of surface sizing agent ratio and calendering treatment on the diffusion behavior of fluid in the microfluidic channel.First,the cellulose paper was hydrophobically modified by using a surface sizing agent with a ratio of 7∶3(m_(surface sizing starch)/m_(AKD)),and then the modified paper was calendered at the pressure of 2 MPa with a speed of 3.5 m/min.The results demonstrated that constructed microfluidic channel exhibited an excellent liquid limiting performance.In these hydrophilic channels,the liquid can achieve a complete directional diffusion,and the z-direction liquid diffusion problem was also solved.Finally,the paper-based chip was further applied for the quantitative detection of nitrite,which shows that there is a good correlation between the solution mass concentration and the color difference value of the chip surface.The corresponding curve fitting equation is y=1.799+8.745 x^(0.453)and the correlation coefficient is 0.9935.