Sensitive detection of sulfide ions in red region based on luminescence resonance energy transfer between upconversion nanoparticles and dye‐670

Many sulfides are toxic substances, which are easy to harm the respiratory tract, thus affecting the respiratory function, or damage other organs of the body, leading to its failure. Therefore, it is of great significance to develop a method for the sensitive detection of sulfur ions (S2- ). Based on the theory of luminescence resonance energy transfer (LRET), we report the construction of a NIR excitation luminescence probe with NaGdF4 :Yb3+ ,Er3+ @NaYF4 upconversion nanoparticles (UCNPs) as the donor and dye-670 as the receptor for the detection of S2- . When UCNPs and dye-670 molecules are combined by ligand exchange and electrostatic attraction, LRET occurs and the luminescence of UCNPs is quenched. When S2- is added to the system, sulfide ions can destroy the double bondof the dye, inhibit the LRET and restore the luminescence of UCNPs. Under the optial condition, the linear range of S2- detection is 0.65-18.2 μM, and the detection limit is 34.2 nM. The method has been applied to the determination of S2- in water with satisfactory results.