Development of inorganic-organic hybrid nanostructured material for H2O2 sensing application

An organic-inorganic hybrid nanoparticle (HNPs) composed of Sm(TTA)3Phen, a coordination compound, and NaY0.78Er0.02Yb0.20F4, an upconversion nanoparticles (UCNPs), has been developed and used for H2O2 sensing application. Herein, Sm(TTA)3Phen absorbs ultraviolet (UV) light and gives fluorescence in yellow-red-near infrared (NIR) region. Whereas, the UCNPs absorb NIR radiations (980 nm) and consequently emit in green-red region through photon upconversion process. Two important optical phenomena are observed when HNPs are simultaneously excited with UV (266 nm) and NIR (980 nm) laser radiation- (i) an energy transfer from Sm3+ to Er3+ ions, and (ii) color tunable emission from red to green, if the power of 980 nm laser is varied. Further, the material is highly competent to sense H2O2 through fluorescence quenching of Sm3+ emission in presence of H2O2. The nature of quenching is conspicuously different for different concentration/volume range of H2O2. For lower volume range, the rate of decrease of emission/excitation intensity is linear, while for higher volume range the decay in intensity is exponential. The attained minimum detection limit for H2O2 is 2 l, which is significant for sensing applications.