Luminol-Based Glucose Detection using the Smartphone Camera
This work reports the detection of glucose using a smartphone camera. The camera captured chemiluminescence generated by the enzymatic reaction performed in a paper-based microfluidic device. The glucose oxidase enzyme catalyses oxidation and further hydrolyzation of glucose into gluconic acid and releases hydrogen peroxide. The hydrogen peroxidase produced in the reaction causes oxidation of luminol. This reaction was accomplished in a microfluidic device by coating the enzyme and luminol solution on two different nitrocellulose paper discs of 3 mm diameter. These two discs were placed on two different microfluidic plates (upper and lower plate). After the reaction of luminol with hydrogen peroxide, a proportional glow with respect to the concentration of glucose was generated. This glow was captured using the smartphone camera and the image was processed using a Python-based image processing algorithm. The image processing involved the calculation of the mean pixel intensity of the glowing region by eliminating the background from the image and defining contours in the image. The intensity values mapped with the glucose concentration had a coefficient of determination of 0.99. Keywords - Glucose, Python, Smartphone, Chemiluminescence, Luminol.