Label-Free Bound-States-in-the-Continuum Biosensors.

Bound states in the continuum (BICs) have attracted considerable attentions for biological and chemical sensing due to their infinite quality ( Q )-factors in theory. Such high- Q devices with enhanced light-matter interaction ability are very sensitive to the local refractive index changes, opening a new horizon for advanced biosensing. In this review, we focus on the latest developments of label-free optical biosensors governed by BICs. These BICs biosensors are summarized from the perspective of constituent materials (i.e., dielectric, metal, and hybrid) and structures (i.e., grating, metasurfaces, and photonic crystals). Finally, the current challenges are discussed and an outlook is also presented for BICs inspired biosensors.