Nanodomain-Enhanced\nStable and Multifunctional Probes\nwith Near 100% Quantum Yield for Versatile Biosensing

The preparation of high quantum yield, stable, and multifunctional\nfluorescent probes is of great significance in the fields of biomedicine\nand photoelectric sensing. Here, a triphenylamine-based D−π–A\nfluorescent molecule (TPA-CN) was designed and prepared, demonstrating\na fluorescence quantum yield of 88.84%. With a polystyrene nanosphere\nas the carrier, TPA-CN was encapsulated inside the nanosphere to form\nintra-nanosphere confining domains. These nanodomain-enhanced fluorescent\nnanospheres exhibited a fluorescence quantum yield of 98.21%. Using\nantigen–antibody specificity and the selective catalytic activity\nof a bioenzyme, with chloramphenicol as a model target, a dual-signal\nreadout biosensor (in fluorescence and colorimetric modes) was designed\nfor ultrasensitive and instrument-free determination. The detection\nlimit was 24 pg/mL within 30 min in fluorescence mode, 38-fold more\nsensitive and 10-fold faster than that of enzyme linked immunosorbent\nassays. The nanodomain-enhanced fluorescent probes and dynamic biosensor\nprovide a robust and versatile solution for public health and environmental\nmonitoring needs.