材料期刊网

To achieve a stable, sensitive, and high-efficiency biological probe, a novel NaYF4:Yb,Er nanocrystals/TiO2 inverse opal composite film was designed by self-assembly and solvent evaporation methods. 32-fold enhanced upconversion (UC) emission was investigated under 980 nm excitation. According to size-dependency, excitation power density-dependency as well as photonic stop band (PSB)-dependency upconversion spectra, the enhancement mechanism of the composite film was put down to the stochastical diffraction of IOPCs multi-layered structure to the excitation laser. On the basis of the enhancement effect of the composite film, en-ergy transfer between upconversion nanoparticles (UCNPs) and quantum dots (QDs), and the sensitive sensing of CdTe QDs on mercury, the UC composite film was used for sensing of Hg2+ in serum. The solid sensor as a mercury detector owns lots of superior-ities such as feasible operation, good linear relationship (R=0.997), low limit of detection (70.5 nmol/L) and thus may have broad prospects in the biosensing field.