Smartphone-assisted fluorescent microfluidic-chip for sensitive detection of sweat glucose via dual-sensing of O/HO.

A novel smartphone-assisted fluorescent microfluidic-chip was designed for detecting sweat glucose. The microfluidic chip contained six microchambers, each of which was equipped with a glucose sensing membrane incorporating glucose oxidase (GOD), fluorescent O probe PtTFPP and HO probe G1. Based upon O consumption and HO generation during glucose catalysis by GOD, the chip produced two fluorescence signals towards glucose under single-wavelength excitation, i.e. green fluorescence in response to HO and red fluorescence to O. The limit of detection (LOD) based on HO monitoring was 0.005 mM, while the LOD based on O monitoring was 0.04 mM. Furthermore, the obtained chip was integrated with a smartphone-based portable platform to record RGB values for point-of-care testing of sweat glucose. Glucose calibration (Y = -3.45 + 1.81∗R + 0.68∗G) at 6-min time point was performed by combining R and G channels signals. The dual-monitoring analysis provided a more accurate and reliable verification of glucose detection. This smartphone-assistant optical microfluidic-chip device holds significant potential for portable self-management of glucose in personalized healthcare and clinical diagnosis.