| 초록 |
The near infrared (NIR) region is of great interest in bio-imaging applications because of minimal auto fluorescence, and reduced light absorption and scattering. We demonstrate the potential of heavy-metal-free quantum dots (QDs), CuInS2/ZnS (CIS/ZnS), which have desirable optical properties and less toxicity. We synthesize CIS/ZnS QDs with a high quantum yield at various emission spectra from visible to NIR region (570-730 nm) using a simple heating-up method. The emission spectrum is controlled by changing the feeding Cu/In ratio of the CIS core from 1/4 to 2/1. The CIS/ZnS QDs are transferred from dichloromethane to an aqueous solution via an emulsification technique with Human serum albumin and six-armed polyethylene glycol (PEG). The multi-armed PEG-coated QD/PEG nanocapsules show excellent dispersion stability in aqueous solution and exhibit a high luminescence efficiency. Preliminary in vitro studies also show that the NIR CIS/ZnS QDs are more suitable for deep-tissue imaging as compared to visible-light-emitting QDs. |
