Compact Fluorescence Detection System for Polymerase Chain Reaction Chips

In this paper, we propose a compact system for the fluorescence detection of polymerase chain reaction (PCR) chips. Various fluorescence detection methods have been proposed, but all require many optical components and optical distances. In contrast, in this paper, we propose a system for detecting fluorescence by attaching an LED and a photodiode directly to the reagent surface. The system is very compact and inexpensive because it requires only excitation and emission filters. To optimize the performance of the proposed system, LED and photodiode arrangements, selection of filters, and signal amplification circuits were investigated. The modification of the PCR protocol to obtain better results was also investigated. PCR amplification experiments on real DNA samples showed that the proposed system works well.