High sensitivity fluorescence detection using smart phone cameras

A low cost and highly sensitive fluorescence detection system using smart phone cameras was developed for biological and biochemical detection experiments. The system was designed for standard 96-well plates, which are typically used in life-sciences laboratories. Traditional fluorescence detection is done using specialized optics, filters and ultra-sensitive detectors such as photo-multipliers, which makes the system expensive. In our method, the 96-well plate is imaged using a smart phone camera inside a light tight enclosure. No specialized filters are used for the imaging. The image is then analysed using an algorithm, developed by us, that separates out the Red-Green-Blue (RGB) component. The Green component is then further processed to extract the fluorescence intensity. The developed hardware system and the algorithm were tested using two types of samples, fluorescein and Green Fluorescent Protein (GFP) incorporated yeast cells, prepared in varied concentrations. The performance of the developed system was compared with measurements taken using a PerkinElmer VICTOR™ X5, 2030 Multilabel Reader. Our system is capable of reliably detecting 1 nM concentrations of fluorescein. We believe the system can be improved further to detect even lower concentrations.