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 Tb3+, Ga3+, 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 Tb3+. 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.