Photostable o -Carborane-DAPA Hybrids for On-Site Nitrite Screening: Dual-Mode Detection Achieving Sub-100 nM Sensitivity in Complex Food Matrices

-carborane unit markedly improves photostability and expands the Stokes shift, enabling dual-mode (fluorescence and colorimetric) detection with sub-100 nM sensitivity. DAPA-1CB exhibits outstanding selectivity and sensitivity, distinguishing nitrite from diverse potential interferents even at low concentrations. Notably, the probe achieves accurate recovery rates (92-106%) in complex food matrices such as pickles, bacon, and smoked fish. These findings establish DAPA-1CB as a robust and practical tool for nitrite monitoring and present a promising design strategy for high-performance fluorescent probes in food safety applications.