Laser-etched grooves for rapid fluid delivery for a paper-based chemiresistive biosensor

Paper-based microfluidic devices are an attractive option for developing low-cost, point-of-care diagnostic tools. To incorporate more complex assays into paper, these must become sophisticated, through the sequential delivery of different liquids or reagents without user intervention. Many flow control strategies focus on slowing fluid down. However, this can lead to increased assay times and sample loss due evaporation. We report use a CO2 laser create etched grooves paper accelerate wicking speeds in paper-based devices. explored settings determine optimal configuration. Our findings showed that simply cutting slit created fastest channels. The acted as macro capillary, allowing bypass speed it up. Further studies determined ideal groove pitch 0.75 mm (spacing between grooves) channel. Additional experiments documented how sealing grooved channels with adhesives influence wicking. Overall, tape made them wick faster. methods such lamination had negative effect Laser-etched were successfully used design fluid-handling architecture chemiresistive biosensor. facilitated rapid, wash buffer. Human serum albumin spiked phosphate buffer, artificial urine, saliva was detected at low 15 pM. Etching is simple process requires no additional materials chemicals, single-step fabrication