NaYF4:Yb3+(58%),Tm3+@NaYF4@Au nanocomposite for 4-nitrophenol ultrasensitive quantitative detection and highly efficient catalytic reduction

4-Nitrophenol (4-NP) is one of the main toxic water pollution substances. Most 4-NP fluorescence detection methods are based on the change in the fluorescence intensity of a single emission peak, which has low sensitivity, accuracy, and narrow analytical ranges. Herein, NaYF4:Yb3+(58%),Tm3+@NaYF4@Au were designed and synthesized for the quantitative detection of 4-NP due to the fluorescence intensity ratio of two upconversion emission peaks, the analytical range is 0.01-100 mu g mL(-1) and the detection limit is 0.01 mu g mL(-1). In addition, 1.66 nm Au nanoparticles randomly distributed on the surface of composite nanomaterials can effectively cause the catalytic reduction of 4-NP. Therefore, NaYF4:Yb3+(58%),Tm3+@NaYF4@Au is a type of composite nanomaterial with great development potential and application prospects in the detection and catalysis of 4-NP.