Bound states in the continuums (BICs) have attracted extensive attention in biological and chemical sensing. This is because they can significantly confine the light field and enhance light?matter interactions at the sub-wavelength scale. Currently, we have witnessed the emergence of several metaphotonic devices based on BICs. These devices are expected to break through the limitations of traditional biosensing in aspects such as miniaturization, specificity, and sensitivity. In this review, starting from BICs-based metaphotonic devices on different platforms, we systematically summarize the applications of metallic BICs, all-dielectric BICs, hybrid metal?dielectric BICs, and microfluidic BICs in biosensing fields, including refractive index sensing, surface-enhanced infrared absorption spectroscopy, and chiral sensing. Finally, we also explore the current limitations of BICs-based biosensor devices and discuss potential solutions to overcome these challenges in the future.