A regenerable and reducing false-positive fluorescent switch for detection of β-amyloid _1-42 oligomers

The conventional fluorescence analysis methods for disease identification are vulnerable to the restriction with false-positive. Here, a fluorescent switch with high efficiency and regeneration by the black phosphorus (BP) nanosheets-regulated was developed to overcome false-positive issue in the assay of β-amyloid_1-42 oligomers (Aβ) process. The Aβ was rapidly recognized using the fluorescent emitter-nitrogen-doped carbon nanodots (N-CDs) under the regulation of BP nanosheets, while the N-CDs alone cannot recognize Aβ without the introduction of BP. The fluorescence analysis methods exhibited a wide sensing range of 0.25-15.0 ng/mL and a low detection limit of 83 pg/mL for Aβ analysis, which was superior to the reported fluorescence analysis method. Further, BP nanosheets were recycled, demonstrating the fluorescent switch with highly efficient, stable, and regenerable. This provides a new idea for developing high-efficiency and high-precision fluorescence detection platform.