Synthesis of a NIR fluorescent dye and its application for rapid detection of HSO3- in living cells

SO2 and its derivatives (HSO3-, SO32-) play a significant important role in many industries and organisms. Based on coumarin and benzopyranose, a promising NIR ratiometric fluorescent probe BAOA (11-oxo2,2 ',3,3 ',6,7,7 ',8 '-octahydro -1H,1 ' H,5H,6 ' H,11H-[10,12 '-bipyrano [2,3-f] pyrido [3,2,1-ij] quinolin]-13 '-ium perchlorate) was designed and developed to detect HSO3- rapidly and sensitively. The sensing mechanism was Michael addition reaction, in which, strongly nucleophilic HSO3- attacked carbon-carbon double bonds and BAOA-HSO3 was formed. A superior linear calibration curve between the fluorescence ratio I-490/I-722 and concentrations of HSO3- was obtained in the range of 1.25-8.75 mu mol/L and the LOD was figured out as 63.0 nmol/ L. Cell experiments showed that BAOA could not only locate mitochondria, lysosomes, ER and Golgi but also detect exogenous HSO3- in living cells.

Automated summary

BAOA, a novel fluorescent probe, was designed for rapid and sensitive detection of HSO3- in both industrial and biological settings. It also demonstrated targeting capabilities within cells.