Engineering a triplet exciton enhanced photoluminescence self-assembled nanoprobe containing block copolymer and Tb3+/Ga3+ complex for fluoride ion detection in serum

The fluoride ion (F – ) concentration in serum is an important indicator of fluorosis. However, the biofluorescence of serum itself makes the concentration of F – difficult to detect. Herein, a Tb‐1@F127 nanoprobe is synthesized by Flash NanoPrecipitation of Tb 3+ , Ga 3+ , organic ligands and block copolymer Pluronic (F127). The absorbance and photoluminescence (PL) of the Tb‐1@F127 nanoprobe are enhanced by the "antenna" effect of the organic ligands and the energy transfer of triplet excitons . The molar extinction coefficient of Tb‐1@F127 nanoprobe is 28,000 times higher than the f-f transfer in free Tb 3+ . Moreover, the addition of F – blocks the above energy transfer process , resulting in a decrease in the PL intensity of Tb‐1@F127 nanoprobe. In the serum solution, the PL intensity of Tb‐1@F127 nanoprobe has a linear response to the concentration of F – in the range of 0–18.81 ppm, and the detection limit is 0.056 ppm. The Tb‐1@F127 nanoprobe demonstrates high sensitivity and selectivity for the detection of F concentration, and is not affected by biological autofluorescence.