A long lifetime ratiometrically luminescent tetracycline nanoprobe based on Ir(III) complex-doped and Eu3+-functionalized silicon nanoparticles

Different from fluorescent dyes-doped or carbon materials-based ratiometric tetracycline nanoprobes, herein, a new Ir(III) complex-doped and europium(III) ion (Eu 3+ )-functionalized silicon nanoparticles (Ir(III)@SiNPs-Eu 3+ ) with long luminescent lifetimes was firstly fabricated for selective detection of tetracycline (TC) in complex systems through time-resolved emission spectra (TRES) measurement. In the presence of TC, the red phosphorescence of Eu 3+ is greatly enhanced by adsorption energy transfer emission (AETE) of TC, while the strong green luminescence of Ir(III)@SiNPs is quenched by the inner filtration effect (IFE) of TC. Based on these striking emission changes, Ir(III)@SiNPs-Eu 3+ can sensitively detect TC in the linear range of 0.01–20 μM with a detection limit of 4.9 × 10 –3 μM. Benefitting from the long lifetime of Ir(III)@SiNPs-Eu 3+ , the nanoprobe demonstrates excellent TC detection performance through TRES in high background system of 5 % human serum. Furthermore, the formed Ir(III)@SiNPs-Eu 3+ /TC complex can be used to sensitively recognize Hg 2+ via a ratiometric luminescence mode. Notably, the cytotoxicity of Ir(III)@SiNPs-Eu 3+ is very low and thus the sensitive monitoring the detection of Ir(III)@SiNPs-Eu 3+ to TC and Hg 2+ also works well in porcine renal cells, demonstrating high application potential in real samples.