Multi-step particle-based microfluidic test for biotin measurement

Microfluidics has emerged as a highly promising technology for miniaturizing chemical analysis laboratory into a single, small lab-on-a-chip device. In our previous research, we have developed an innovative approach to particle-based microfluidics by screen printing silica gel microparticles onto glass substrate to create a patterned porous material. In this article we demonstrate a multi-step sample analysis - combining conventional and affinity thin-layer chromatography with competitive assay for detection - along with blister reservoirs that can be integrated into the particle-based microfluidic point-of-care test. This integration achieves high analytical performance and makes the test simple to use. Biotin was chosen as the exemplary analyte, because measuring it is crucial in immunoassays, where high circulating biotin concentrations can lead to false results. This research also addresses the challenge of biotin interference in immunoassays by making it possible to produce rapid biotin tests. Need for these tests is particularly critical in emergency situations. Validation of the developed test demonstrated a dynamic range of 0.09 to 0.24 mu g ml- 1 and that artificial urine matrix does not have significant effect on the results. This would make it possible to assess whether the biotin interference occurs in urine sample immunoassays.