Luminescent NaTb(SO4)2 nanoprobe for hydrogen peroxide based on switchable fluorescence of Tb(IV)/Tb(III) redox couple

The accurate and sensitive detection of hydrogen peroxide (H 2 O 2 ) is of practical significance in the fields of bioanalysis, medicine, environmental protection as well as food industry. Herein, we design and fabricate NaTb(SO 4 ) 2 nanoparticles (NPs) as novel fluorescent nanoprobes for H 2 O 2 detection. The design strategy is based on the fluorescence quenching occurred during the oxidation of Tb(III) to Tb(IV) upon H 2 O 2 addition. The sensing of NaTb(SO 4 ) 2 NPs to H 2 O 2 is in a “turn-off” mode, and the sensitivity is tunable by the pH due to the pH-dependence of the oxidizing ability of H 2 O 2 . Superior to most of the reported H 2 O 2 sensors, NaTb(SO 4 ) 2 NPs exhibit reliable stability in acidic environment and a more sensitive response to H 2 O 2 with a limit of detection (LOD) down to 0.047 μM at pH = 3.2. Based on its high sensitivity and reliable stability, the NaTb(SO 4 ) 2 NPs is anticipated to find potential applications in the field of biosensors.