Date of Award
Master of Science in Mechanical Engineering and Applied Mechanics
Mechanical, Industrial and Systems Engineering
This study presents the development of a 3-fluid microfluidic device for the application in immunoassays. The test uses a microfluidic valve in order to sequentially load the reagents autonomously onto the detection area after adding the sample. The development of the multi-fluid circuit allows the application of an enzyme-linked assay in a lateral flow device as to provide with an improved sensitivity compared to strip tests available on the market. For fabricating the channels of the device, a wax printer was used. The layers were attached using double-sided tape. In order to advance the reliability of the device, new fabrication method were applied in this study. After optimizing parameters such as reagent concentrations, reagent volumes and the dimensions of the device, a calibration curve using rabbit IgG was created. The limit of detection was then obtained. Furthermore a housing for the device was developed. By compressing the microfluidic valve, an improved reliability of the valves was obtained. For the goal of an autonomously running device, a reagent storage was incorporated into the housing. The reagent storage provides with the ability to operate the test without additional interference after adding the sample. Based on the results of this study, an improved lateral flow test was obtained. The developed 3-fluid device using an enzyme-linked assay is able to detect rabbit IgG down to a concentration of 4.7 ng/ml. This results in a limit of detection better than in a conventional ELISA conducted on microtiter-plates (8.6 ng/ml). Advantages such as lower reagent volumes, lower time to result and biodegradability of materials used during the development of this device were achieved.
Föllscher, Wilke, "Development of a Platform for Lateral Flow Test Devices with the Capability of Using Multiple Fluids" (2013). Open Access Master's Theses. Paper 124.