Label-free protein quantitation using liquid crystal-enhanced optofluidic biosensor

Protein detection plays an important role in the medical research. Liquid crystals (LCs), as a class of sensitive materials, exhibit a promising ability in the biosensing field. Herein, we exploited an ultrasensitive biosensor for protein detection, employing the whispering-gallery-mode (WGM) from the LC-amplified optofluidic micro-resonator. The biomolecules can trigger both light-matter interactions and the orientation transitions of LC molecules. The WGM spectral wavelength shift was recorded as the sensing indicator, and a detection limit of 15 fM for bovine serum albumin (BSA) was achieved. Our LC-amplified optofluidic biosensor provides a new solution for the ultrasensitive, real-time, and stable biological detection.