Optical fiber amplifier for quantitative and sensitive point-of-care testing of myoglobin and miRNA-141.

A simple, sensitive, quantitative point-of-care testing (POCT) was developed integrating enzyme-linked DNA supersandwich amplification with optical fiber amplifier. The point-of-care (POC) assay can work in both "Turn-off" mode and "Turn-on" mode. Using myoglobin (Myo) and miRNA-141 as the model biomarker, as low as 0.5 nM Myo and 10 pM miRNA-141 could be detected. More importantly, the optical fiber amplifier, which was used as signal readout, exhibited low-cost, small size, rapid response, and easy operation. Although it did not need large equipment and professional technical personnel, the assay was successfully applied to detect Myo and miRNA-141 in 40% human serum. Since the entire process of the strategy could be done directly in the centrifugal tube, requiring a few easy steps, it showed great potential application for early diagnosis in the world, especially in developing countries or remote regions. This work provided a new avenue for developing the portable and sensitive biosensor.