Fig. 4: H2S sensing in aqueous solutions.

a UCL spectra of UCNPs/CuxOS@ZIF nanoprobes with the addition of H2S. Inset shows the luminescence changes of the corresponding solution under 980 nm laser irradiation. b Plot of the UCL intensity against the concentration of H2S. Inset shows the linear relationship of UCL intensity versus H2S concentration. c CD spectra of UCNPs/CuxOS@ZIF nanoprobes with the addition of H2S. d Plot of the ΔCD (CD481-CD411) against the concentration of H2S. Inset shows the linear relationship of ΔCD versus H2S concentration