An Ultrasensitive Plasmonic Sensor Based on 2D Ferroelectric Bi₂O₂Se

Plasmonic biosensing is a label-free detection method that is commonly used to measure various biomolecular interactions. However, one of the main challenges in this approach is the ability to detect biomolecules at low concentrations with sufficient sensitivity and detection limits. Here, 2D ferroelectric materials are employed to address the issues with sensitivity in biosensor design. A plasmonic sensor based on Bi2O2Se nanosheets, a ferroelectric 2D material, is presented for the ultrasensitive detection of the protein molecule. Through imaging the surface charge density of Bi2O2Se, a detection limit of 1 fM is achieved for bovine serum albumin (BSA). These findings underscore the potential of ferroelectric 2D materials as critical building blocks for future biosensor and biomaterial architectures.