Metal Oxide (ZnO, TiO₂) Layer Affects Sensitivity of Multisample Colorimetric Detection in Microfluidic Paper-based Biosensor

In this work, a measurement setup for glucose level quantification was developed using the colorimetric method on paper-based microfluidic analytical device (µPAD) platform. Separation of blood glucose was assisted with ZnO and TiO2 layer in the hydrophilic zone while the quantification of glucose concentration employed image processing technique by evaluating the intensity of different color spaces including RGB, HSV, and the gray scale. The analysis was carried out by measuring the color intensity at various glucose concentrations to assess the color space that exhibits the best sensitivity and accuracy for measuring glucose levels and the effect of metal oxide layer to the sensitivity of colorimetric measurement. The validation results show that the TiO2-modified µPAD exhibits an average error of 13.4% which is in accordance with the standard. The addition of TiO2 layer leads to a significant change in the average correlation which increased by 34.5% whilst the addition of ZnO decreases the sensitivity by 56.9%.