Patent Pending Technologies

Title: A method to produce water-dispersible highly luminescent quantum dots for biomedical imaging.

Brief description: This invention pertains to the synthesis of CdSe/CdS/ZnS quantum dots in the organic phase using a highly simplified and user friendly methodology, which avoids the use of toxic precursor chemicals and long synthetic time. These quantum dots can then be easily dispersed in the aqueous phase using various techniques. The sequential double layering of CdS and ZnS on top of the CdSe core results in uniform deposition of both the layers on the core, which result in extremely high photostability of the QDs. The present synthesis procedure has been optimized to produce large quantities of CdSe/CdS/ZnS quantum dots, having quantum yield as high as 25 - 30%. The high yield production and stability of high quantum yield of CdSe/CdS/ZnS quantum dots in aqueous medium will allow them to be used in bio-imaging, biosensors, and other optoelectronics applications, where high photostability and high concentration of quantum dots are desired.

Title: One-Pot Aqueous Phase Synthesis of Highly Luminescence Core/Shell Quantum Dots.

Brief description: This invention pertains to the synthesis of CdTe/ZnTe quantum dots directly in the aqueous phase. There are two distinct advantages of this technology. First, their direct, one-step synthesis in aqueous phase, as opposed to the traditional two-step synthetic method involving synthesis in non-aqueous phase followed by transfer in aqueous phase, will lead to extremely simplified and uniform production methodology. Second, the use of a CdTe core, as opposed to the traditionally used CdSe core, will lead to tunability of the emission of the QDs in the near infra-red (NIR) region, which is ideal for biomedical applications. The present synthesis procedure is developed to produce high yield of core/shell quantum dots, having quantum yield as high as ~55%. The emission wavelength of the quantum dots can be easily tuned from ~500 to ~900 nm by changing the core size and composition of the dots. The high yield production and quantum yield of the QDs in aqueous medium will allow them to be used in bio-imaging, biosensors, and other optoelectronic applications, where high optical stability and high concentration of QDs are generally required.