A 96-Well LED Array for Multiplexed Photoelectrochemical\nDetection of Nucleic Acids

Photoelectrochemical\ndetection of nucleic acid-based cancer biomarkers\noffers opportunities for highly sensitive, selective, and fast quantitative\ndetection using low-cost measurement instruments. In order to establish\nitself as a standard method for identifying and quantifying nucleic\nacids, we have developed a multiplexing strategy using LED technology\nfor photoelectrochemical detection in 96 samples simultaneously. A\ndedicated setup based on the 96-well plate configuration with a custom-made\n96-well LED array was developed. Subsequently, a proof-of-concept\nstudy was performed for three miRNAs that are associated with prostate\ncancer, i.e., miRNA-141, miRNA-145, and miRNA-375. First, measurements\nwith photosensitizer chlorin e6 and redox reporter hydroquinone free\nin solution proved the proper functioning of the multiplexed detection.\nSecond, the photoelectrochemical detection of the three miRNAs at\n24 nM levels was successfully demonstrated. Thereafter, linear calibration\ncurves (<i>R</i><sup>2</sup> > 0.9 for all analytes)\nwere\nmade with plasma spiked with 8–500 pM miRNA. This work presents\nthe first system for multiplexed high-throughput photoelectrochemical\ndetection, allowing it potentially to become a cost-effective and\nfaster alternative to RT-qPCR and gene sequencing techniques in the\nfuture.