Researchers at the National University of Singapore (NUS) in partnership with the scientists at the Fujian Institute of Research on the Structure of Matter and the King Abdullah University of Science and Technology have developed an efficient upconversion technique in nanoparticles, paving the way to efficiently control light emission utilized in imaging applications.
The researchers discovered a chemical pattern that is capable of demonstrating superior upconversion properties based upon a unique energy level arrangement. Their lanthanide-doped core-shell nanocrystals demonstrate novel optical properties that can manipulate light for heating, making them suitable for drug delivery and photodynamic therapy applications. Ministry of Education of Singapore and A*STAR funded the research work.
The scientists tried to manipulate the nanoparticles’ optical properties by adding rare earth metals as dopants in closed layer-by-layer patterns. Various rare earth metals can be used as dopants with nanomaterial shell, offering more options of the upconverted emission tunability. By synthesizing nanomaterials with tunable emission and low toxicity, the scientists have achieved a major landmark in the synthesis of upconverting materials. Their innovative method for synthesizing core-shell nanoparticles allows the isolation of upconversion process from that of the emission of light. The core of the nanomaterials absorbs photons and converts them into excited electrons, which then moved towards the rare earth dopants that are in the excited state within in the shell where these electrons calm down and release light.
The researchers synthesized nanomaterials that can deliver upconverted luminescence ranging from red yellow, green, blue, violet, with radically lengthier infrared excitation wavelengths to a maximum of 980 nm. The light having 980-nm wavelength delivers high transparency of living tissues in infrared, improving the chances of using these nanomaterials for detecting cancer. Moreover, the emission of multiple colors illustrated in this study makes these materials to be used as multiple cell markers.
According to the researchers, the findings pave the way to develop a broad array of luminescent upconversion nanocrystals having unique spectroscopic fingerprints. The lanthanide-doped nanocrystals’ low toxicity and light control capability make them suitable for light-control drug delivery for target-specific delivery and promises future medicines with minimal side effects. The researchers identified the novelty of their design, which utilizes gadolinium ions and core-shell nanoparticles for energy propagation that allows the production of a broad array of lanthanide-doped nanocrystals to offer upconverted luminescence. The NUS research team has recently submitted a patent application for its innovative approach and is collaborating with clinicians to devise clinical diagnostic models for practical applications.