Fig. 1

a Schematic illustrations of the influence of fluoride ions on the photothermal activity of CeO₂ + TMB reaction. b Photothermal heating curves of CeO₂, F⁻, TMB, CeO₂ + F⁻, CeO₂ + TMB, and CeO₂ + F⁻ + TMB under 808 nm NIR laser irradiation at 2.3 W/cm². Concentration: CeO₂ (30 µg/mL), F⁻ (5 mM), TMB (1 mM), acetate buffer (pH 4, 20 mM). c Heating and cooling cycles of CeO₂ + F⁻ + TMB system (CeO₂: 30 µg/mL, F⁻: 5 mM, TMB: 1 mM) under on–off cycles. d Photothermal effects, and e corresponding curve fitting of cooling time versus the negative natural logarithm of the driving force temperature during the cooling phase of CeO₂ + TMB (CeO₂: 30 µg/mL, TMB: 1 mM) with and without fluoride ions. f The linear calibration plots of temperature readings against the various fluoride ions concentrations (0–5000 µM). g Relationship between temperature change values from the NIR laser irradiation (808 nm, 2.3 W/cm²) under different circumstances of Al³⁺ concentration