Rolling Circle Amplification in Bead-Based Microfluidic Device with Integrated Photodiode for Fluorescence Signal Transduction

The detection of pathogens in primary care settings is critical, not only for virus detection but also for the detection of antibiotic resistant bacteria. Microfluidic devices can be used to develop point-of-care detection systems, but are usually insufficiently sensitive for the application. An on-chip isothermal amplification technique, such as the padlock probing-based rolling circle amplification technique, could potentially achieve the desired specificity and sensitivity, while keeping the complexity of the microfluidic device low. In this work, we describe an innovative microfluidic rolling circle amplification performed on microbeads using a continuous flow of solutions with the potential to achieve the required clinical demands in fast and sensitive fashion. Moreover, the integration with amorphous-hydrogenated silicon thin film p-i-n photodiode and a high-pass interference filter to allow the acquisition of the fluorescence signal from the amplification product on-chip, demonstrates the capability of performing the full assay on-chip along with the portability potential of the device.