Glucose and cholesterol sensing in blood plasma using zno-paper based microfluidics

This work aims at investigating the reliability of ZnO-paper based microfluidic analytical devices (ZnO-μPAD) for blood plasma separation as well as bio-sensing of glucose and cholesterol. Two-layer paper-based microfluidic analytical devices coated with ZnO nanoflowers/ZnO spherical aggregates (ZnO-μPAD) for a rapid blood plasma separation and glucose sensing were developed. Plasma separation in ZnO-μPAD was evaluated experimentally and numerically using computational fluid dynamics package for a flow over porous networks. Glucose and cholesterol detection was carried out using spectroscopic techniques, both Fourier-transform infrared (FTIR) and Raman measurements. The plasma separation process on ZnO NF-μPAD requires 250 s. The spectroscopic investigation reveals that the IR absorptions and Raman signals at the typical vibrational frequencies of glucose and cholesterol are increasing at higher concentration. After subtraction from absorption background arising from ZnO and the paper, a specific and linearly increasing IR absorption (913 and 1349 cm^-1) and Raman signals (1346 and 1461 cm^-1) are observable with a relatively good sensitivity.