Reassembling smartphone with liquid crystal display panel into a new optical transducer for point-of-care sensing application

We developed a smartphone-based optical transducer employing the light-interference and wavelength-filtering principles. To materialize this, we prepared the optical signal-guide, containing multiple polygonal figures composed of specified color-ratio, on the digital display. When the biosensing channel, which can induce the enzyme-mediated chromogenic reaction, was located between the signal-guide and smartphone camera as a color-filtering layer, the number of observed signal-guide patterns would be changed by the absorbance changes in biosensing channel, leading the absorption of specific light from the signal-guide patterns. Based on this transducing principle, we could quantify the biomarker concentration by counting the number of patterns.