Tape integrated self-designed microfluidic chip for point-of-care immunoassays simultaneous detection of disease biomarkers with tunable detection range.

Multiple biomarkers to diagnose the combined manifestations of a patient's disease are an indispensable guide in point-of-care testing (POCT) and clinical applications. Currently, multiplex determination of molecules at different concentrations usually requires assays with adjustable detection ranges. Here, for the first time, commercially available 3M tapes, Tape 610, Tape 810, Tape 600, are integrated into a self-designed key valve microfluidic chip (KVMC) to construct a Tape-based KVMC. Interestingly, 3M tapes with different absorption tunability for the encapsulated antibodies have been used in KVMC as substrate to enable detection of diseases biomarkers in serum ranging from pg mL to μg mL. The Tapes antibody layer in the chip has been successfully developed without sophisticated modifications, and the detection probe can be used for a wide range of detection of three biomarkers without multiple modifications and amplification. Automated, multiplexed, simultaneous bioassays of clinically relevant inflammatory biomarkers are performed in the Tape-based KVMC POCT system, with a limit of detection (LOD) of 0.23 μg mL for C-reactive protein (CRP), 0.14 ng mL for procalcitonin (PCT), and 12.53 pg mL for interleukin-6 (IL-6), respectively, which offers a desirable strategy for the early clinical diagnosis of sepsis. The developed Tape-based KVMC possesses high sensitivity and excellent selectivity for three biomarkers in undiluted human serum samples, providing the foundation for the application of chip POCT in clinical and field precision diagnostics.