An IoT Based Smart Optical Platform for Colorimetric Analyzing Multiple Samples of Biomarkers

In this work, an IoT-enabled optical platform as a colorimetric analyzer for disposable rapid diagnostic chips has been designed, implemented, and characterized. Color image of the test chip has been taken utilizing an external camera module and analyzed using an image processing algorithm, both incorporated with an IoT-enabled single board minicomputer. To dodge the image burning a unique light-diffusing model has been proposed and to reduce ambient lighting impact, a strategic distance has been maintained within the white acrylic made imaging enclosure of the platform. To optimize the even optical environment, a study on the incorporation of a highly bright single LED and a LED array in the platform has been carried out using a custom-made single-channel test chip containing blood hematocrit. Based on the optimized light incident angle for the LED array, a PDMSmade light diffuser has also been installed with an LED array to ensure even and uniform distribution of light on the sample. Finally, with the image processing algorithm, the proposed device has been successfully applied for the detection of blood hematocrit, β-hCG, and SARS-CoV-2 antigen identifying their different level of concentration. Since the device is portable in size and cost effectively implementable, it can likewise be utilized for analyzing other biomarkers in the resource limited communities for point-of-care (POC) applications.