Development of Upconversion Luminescent Probe for Ratiometric Sensing and Bioimaging of Hydrogen Sulfide

Merocyanines adsorbed into the mesopores of mSiO₂ shell of NaYF₄: 20% Yb, 2% Er, 0.2% Tm nanocrystals are demonstrated as ratiometric upconversion luminescence (UCL) probe for highly selective detection of HS^– in living cells through inhibition of energy transfer from the UCL of the nanocrystals to the absorbance of the merocyanines. The UCL probe has been used for ratiometric sensing of H₂S with high sensitivity and selectivity