A compact, low-cost, quantitative and multiplexed fluorescence detection platform for point-of-care applications

Abstract

An effective method of combating infectious diseases is the deployment of hand-held devices at the point-of-care (POC) for screening or self-monitoring applications. There is a need for very sensitive, low-cost and quantitative diagnostic devices. In this study, we present a low-cost, multiplexed fluorescence detection platform that has a high sensitivity and wide dynamic range. Our system features inexpensive 3 × 3 mm interference filters with a high stopband rejection, sharp transition edges, and greater than 90% transmission in the passband. In addition to the filters, we improve signal-to-noise ratio by leveraging time for accuracy using a charge-integration-based readout. The fluorescence sensing platform provides a sensitivity to photon flux of ∼1×104photons/mm2sec and has the potential for 2–3 orders of magnitude improvement in sensitivity over standard colorimetric detection that uses colored latex microspheres. We also detail the design, development, and characterization of our low-cost fluorescence detection platform and demonstrate 100% and 97.96% reduction in crosstalk probability and filter cost, respectively. This is achieved by reducing filter dimensions and ensuring appropriate channel isolation in a 2 × 2 array configuration. Practical considerations with low-cost interference filter system design, analysis, and system performance are also discussed. The performance of our platform is compared to that of a standard laboratory array scanner. We also demonstrate the detection of antibodies to human papillomavirus (HPV16) E7 protein, as a potential biomarker for early cervical cancer detection in human plasma.