纸基微流控芯片刻蚀法条件优化及其在沙门氏菌检测中的应用

：目的 优化纸基微流控芯片刻蚀法制备条件，并研究改性滤纸的微观结构和性能。方法 制作压切式模具，结合模切机压切出亲水基底模型，考察硅烷化修饰时间、不同型号滤纸、三甲氧基硅烷溶液浓度、不同类型表面活性剂及其浓度和刻蚀时间对纸基微流控芯片的影响，通过滤纸接触角变化、扫描电子显微镜（scanning electron microscope，SEM）和X射线能谱仪（energy dispersive X-ray，EDS）分析纸基微流控芯片改性前后的表面微观结构和元素变化，再将纸基微流控芯片用于沙门氏菌检测比色分析。结果 选用Whatman No.1滤纸作为最佳疏水基底，三甲氧基硅烷溶液最适浓度为8%，浸泡时间为3 min，十二烷基硫酸钠（sodium dodecyl sulfate，SDS）溶液为亲水通路最佳的表面活性剂，最适浓度为1%，最佳刻蚀时间为4 min；SEM显示了滤纸改性后其表面生成一种膜状结构；EDS元素分析结果表明疏水剂处理滤纸Si含量达到0.87%，亲水化处理后Si含量降为0.25%，刻蚀效果显著，比色法检测沙门氏菌获得了良好的线性关系。结论 得到了刻蚀法制备的纸基微流控芯片的最优条件，并成功应用于比色法检测沙门氏菌，研究将为其微量化、低成本、便捷化的应用提供技术和理论依据。

Optimization of etching method for paper-based microfluidic chip and its application in Salmonella detection

Objective To optimize the preparation conditions of paper-based microfluidic chips by etching, and the microstructure and properties of modified filter paper were studied. Method Hydrophilic substrate models were prepared by die-cutting machines and self-made press-cutting mold. The effects of silanization modification time, different types of filter paper, concentration of trimethoxysilane solution, different types of surfactants, surfactant concentration and etching time on paper-based microfluidic chips were investigated. The surface microstructure and elemental changes of filter paper before and after modification were analyzed by filter paper contact angle change, scanning electron microscope (SEM) and energy dispersive X-ray (EDS). Then the paper-based microfluidic chips were used for colorimetric analysis of Salmonella detection. Results Fabrication conditions of paper-based microfluidic chips were optimized by contact angle. The results showed that Whatman No.1 filter paper was the best hydrophobic substrate. The optimum concentration of trimethoxysilane solution was 8%, and the modification time was 3 min. Sodium dodecyl sulfate solution was the best surfactant for hydrophilic pathways, the optimum concentration was 1%, and the optimum etching time was 4 min. SEM showed that a membrane-like structure was formed on the surface of the filter paper after modification. EDS elemental analysis showed the Si content of the modified filter paper reached 0.87 % after hydrophobic agent treatment, and decreased to 0.25% after etching. A good linear relationship was obtained for the detection of Salmonella by colorimetry. Conclusion The optimal conditions for the paper-based microfluidic chips prepared by the etching method were obtained. And detection of Salmonella by Colorimetry with paper-based microfluidic chips. The research will provide technical and theoretical basis for its micro-quantification, low-cost and convenient application.