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

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

中文关键词:  纸基微流控芯片  刻蚀法  优化  表征  沙门氏菌

英文关键词:paper-based microfluidic chips  etching method  optimization  characterization  Salmonella

中文摘要:

      目的 优化纸基微流控芯片刻蚀法制备条件, 研究改性滤纸的微观结构和性能, 并将纸基微流控芯片应用于沙门氏菌的比色检测。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 spectrometer, 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, 将纸基微流控芯片用于沙门氏菌比色检测分析。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, 且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, 并成功应用于沙门氏菌的比色检测。

英文摘要:

      Objective To optimize the etching conditions of paper-based microfluidic chip, study the microstructure and performance of modified filter paper, and apply the paper-based microfluidic chip to the colorimetric detection of Salmonella. 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 spectrometer (EDS). Then the paper-based microfluidic chips were used for colorimetric analysis of Salmonella detection. Results 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 are obtained and successfully applied to the colorimetric detection of Salmonella.