Capillary-driven microfluidic device with integrated nanoporous microbeads for ultrarapid biosensing assays

Abstract

For microfluidic devices to achieve a practical point-of-need application, it is necessary to circumvent the often excessive system complexity required, such as external pumps and multi-step operation, in order to provide a rapid and simple, while still robust and fit-for-purpose device. We report a simple capillary-based microfluidic device with integrated microbeads and a no-wash, single-step mode of operation that achieves a sub-minute detection of analytes using a fluorescent competitive immunoassay. In particular, minimum detectable limits of 1.7 ng/mL were obtained for mycotoxin detection within 70 s assay time, using 4.5 μL of sample. Furthermore, an internal control was also included in the microfluidic device to provide additional robustness and result validation. These results support the development of ultra-rapid and simple microfluidic devices, easily extended to other relevant targets within the food safety, biomedical or environmental fields.