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 (Eu3+)-functionalized silicon nanoparticles (Ir(III)@SiNPs-Eu3+) 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 Eu3+ 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-Eu3+ can sensitively detect TC in the linear range of 0.01-20 mu M with a detection limit of 4.9 x 10(-3) mu M. Benefitting from the long lifetime of Ir(III)@SiNPs-Eu3+, the nanoprobe demonstrates excellent TC detection performance through TRES in high background system of 5 % human serum. Furthermore, the formed Ir(III)@SiNPs-Eu3+/TC complex can be used to sensitively recognize Hg2+ via a ratiometric luminescence mode. Notably, the cytotoxicity of Ir(III)@SiNPs-Eu3+ is very low and thus the sensitive monitoring the detection of Ir(III)@SiNPs-Eu3+ to TC and Hg2+ also works well in porcine renal cells, demonstrating high application potential in real samples.