Mitochondria-targetable camphor-based ratiometric fluorescent probe for real-time detection and dual-channel imaging of hypochlorous acid in foodstuffs and biosystems

The overuse of hypochlorous acid (HClO) during food preservation can destroy the nutrients within foodstuffs, and its overexpression in mitochondria is interconnected with the progression of diverse diseases. Hence, a new mitochondria-targeting camphor-based ratiometric fluorescent probe TPC-HClO was reported for HClO monitoring in foodstuffs and biosystems. TPC-HClO possessed a large Stokes shift of 203 nm and presented a ratiometric response toward HClO with dramatic emission wavelength shift from 568 nm to 438 nm. TPC-HClO was capable of selectively detecting HClO and featured low detection limit (6.2 nM), rapid response time (<60 s), wide pH usage range (5–12), and high photostability (>1800 min). Besides, TPC-HClO could act as a potential method to qualitatively determine HClO residue in foodstuffs with satisfactory accuracy. TPC-HClO was successfully utilized for high-contrast imaging of HClO fluctuations in mitochondria of living cells and applied for real-time visualization of endogenous release of HClO within zebrafish models.