In-situ synthesis and enhanced upconversion luminescence of Y₂O₃/Y₂O₂S:Yb³⁺,Er³⁺/Tm³⁺ nanocomposites by reduction of Y₂O₃:Yb³⁺,Er³⁺/Tm³⁺

Y₂O₃/Y₂O₂S:Ln³⁺ (Ln = Yb,Er and Yb,Tm) nanocomposites with enhanced upconversion luminescence were successfully prepared by combining hydrothermal with in-situ synthesis method. Under 980 nm excitation, the upconversion luminescence intensity of Y₂O₃/Y₂O₂S:Ln³⁺ increased, and then declined with the rising amount of sulfur powder. Especially, the Y₂O₃/Y₂O₂S:Ln³⁺ nanocomposites can emit brighter upconversion luminescence than those of Y₂O₃:Ln³⁺ and Y₂O₂S:Ln³⁺. In terms of Y₂O₃/Y₂O₂S:Yb³⁺,Er³⁺ nanocomposites which were prepared with 0.025g sulfur powder, an unusual ⁴G_11/2 → ⁴I_15/2 and ⁴F_9/2 → ⁴I_15/2 transitions of Er³⁺ could be observed. Besides, we have constructed a simple upconversion Y₂O₃/Y₂O₂S:Yb³⁺,Er³⁺@Au nanocomposite, which can be used for rapid sensing of glucose. The limit of detection of glucose level which based on Y₂O₃/Y₂O₂S:Yb³⁺,Er³⁺@Au was only 0.066 μmol/L. The proposed approach, which we have mentioned above, holds a great practical value for diabetes mellitus detection and clinical diagnosis.