Translating from lab-use to household: Dual-functional upconversion nanoprobes for solar-powered photothermal...

Due to the serious symptoms of brittle bones and endocrine disorders, the common disease fluorosis diminishes quality of life. With the aim of developing probes for both laboratory and household fluorosis diagnosis, in this study we rationally designed a novel dual-functional gallic acid-Fe(III) complex-modified upconversion nanoprobe (DF-UCNP) with simultaneous upconversion luminescence (UCL) and photothermal (PT) conversion capacities. The nanoprobe was feasible for UCL fluorine (F^-) detection with a low detection limit of ∼20 nM and a broad linear range of 0-50 μM, as well as UCL fluorosis diagnosis both in vitro and in vivo for lab-use. Furthermore, by utilizing gathered solar irradiation as a PT excitation source and a digital thermometer as a signal reader, the nanoprobe possessed outstanding PT detection capacities for F^- with a detection limit of ∼100 nM. Based on this nanoprobe and an accessional self-developed Android application, a household PT kit for fluorosis diagnosis was also constructed. This work provides a new method for rapid laboratory fluorosis diagnosis without a cumbersome determination process as well as household fluorosis diagnosis without requiring specific instruments.