On-Chip Self-Referenced Micro-Resonators Enhanced by Digital Optical Frequency Comb for Ultra-Sensitive C-Reactive Protein Detection

An on-chip self-referenced transducer assisted by digital optical frequency comb (DOFC) technology is presented for the biomolecules detection in the lower detecting limit. This self-referenced stricture eliminates temperature cross sensitivity between the detecting and reference micro-resonators fabricated on the chalcogenide glass platform. The high-resolution DOFC technology has the ultra-fine-comb spacers offering for visualized spectral analysis of micro-resonators and capturing the subtle changes of ultra-low concentrations. Combining the self-referenced and DOFC technology, the detection of C-reactive protein in the concentration from 0.1 ng/mL to 500 ng/mL with the theoretically limit of detection of 0.0146 ng/mL is achieved. Given its small footprint, compactness and high analytical performances, the proposed transducing platform has the potential for applications on integration and minimization sensing on a single integrated chip.