Discontinuous nanoporous structures enable low-power electrophoretic immunoassays of serum protein biomarkers

Abstract

To realize low-power electrophoretic immunoassays for protein biomarkers, we introduce discontinuous nanoporous structures photopatterned within microfluidic channels as separation matrices. The discontinuous cross-linked gels enhance analyte mobility differences, therefore reducing the required electrophoretic separation length and electrical potential to complete biomarker detection. An optimized mask-based fabrication protocol is introduced to eliminate protein exclusion and “destacking” dispersion near the pore-size discontinuity. Using the optimized sieving matrix, concurrent quantitation of C reactive protein (CRP) and tumor necrosis factor – alpha (TNF-α) were developed. Both protein species are important in host inflammatory and infection response. The ultra-short separation distance electrophoretic immunoassay reported here provides flexibility in field-portable diagnostic instrument design by relaxing electrical potential requirements and providing multiplexing capabilities.