A smartphone-based colorimetric sensing platform for detection of blood viscosity and hemoglobin

Blood diseases pose a significant threat to human health. Currently, the diagnosis of most blood diseases relies on large-scale professional instruments that require skilled operators in hospitals or commercial laboratories, thereby limiting access to diagnosis in underdeveloped and remote areas. In this study, we propose an innovative smartphone-based colorimetric sensing platform that integrates microfluidic devices based on fluid viscosity and flow characteristics . This platform enables the mixing of two fluids with disparate viscosities at the detection cell by employing microfluidic channels , resulting in discernible alterations in fluid color. It utilizes the ambient light sensor (ALS) of a smartphone to accurately measure the transmittance of the sample under examination, while an Android-based application is employed for result analysis. By altering the fluid composition , respective measurements of two crucial hematology indicators in blood, viscosity and hemoglobin concentration, can be achieved. Moreover, this portable sensor exhibits consistent detection values with those obtained from the state-of-the-art equipment considered as the gold standard and demonstrates a detection limit comparable to it. The presented colorimetric sensing platform offers several advantages of portability, cost-effectiveness, and user-friendly operation, thus rendering it a valuable tool for early diagnosis of a variety of blood diseases, particularly in underserved regions with limited healthcare resources. • A smartphone-integrated colorimetric sensing platform incorporating microfluidic devices . • A portable approach for on-site detection of biochemical markers in blood. • The design of the sensing platform is rooted in an intricate understanding of fluid viscosity and flow characteristics . • The platform allows for the simultaneous assessment of blood viscosity and hemoglobin concentration.