Open-type capillary-assembled microchip for rapid, single-step, simultaneous multi-component analysis of serum sample

Abstract

Here we present an open-type capillary-assembled microchip (CAs-CHIP), demonstrating its ease of fabrication, and use for rapid and simultaneous sensing of different serum components; viz., glucose, cholesterol, and alkaline phosphatase (ALP) and pH. Multiple square glass capillary sensors (outer diameter, 300 μm square) were embedded into a black polydimethylsiloxane (PDMS) microchannel array (300 μm width and depth) generating an open-type CAs-CHIP into which samples were introduced by capillary action. The open-type CAs-CHIP was then embedded into a PDMS reservoir chip where PDMS oil was dropped onto both ends of the capillary to avoid evaporation of the nanoliter sample inside the capillaries. We used fluorescein-based probes to achieve simultaneous multi-component sensing by using a single fluorescence filter and obtained accurate measurements with acceptable day-to-day precision (5.3–8.8%). Discrimination between control and analyte-spiked serum samples was simultaneously accomplished for 4 analytes within 10 min.