Photoluminescence up-conversion of bioconjugated hybrids on CdTe and Au nanoparticles

Semiconductor nanomaterials have attracted considerable attention in the design of high efficiency PL up-conversion in heterojunctions or nanostructures at extremely low continuous wave (cw)-excitation intensity. In this study, bioconjugated hybrids were constructed using CdTe and Au nanoparticles (NPs), where two-fold PL enhancement was observed in the solution state. These results are in accordance with theoretical predictions of the local-field effects associated with the combined influence of strong localization of the collective plasmon modes in metallic-semiconducting hybrids and multi-photon absorption into its localized plasmon modes. The feasibility of the nanohybrids as sensors was demonstrated by breaking the bioconjugation through thermal stress, which induced a rapid decrease in luminescence intensity. It is believed that the phenomena is applicable to high-compacted optoelectronic devices and sensing systems that take advantage of both quantum confinement effects and nonlinear optical properties.