Methods for Making Water Soluble Quantum Dots
AssigneeDrexel University
InventorsWei-Heng Shih, Giang Au, Wan Y. Shih
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Abstract
A novel quantum dot containing two different metals at non-toxic levels which is capable of narrow bandwidth near infrared emissions at wavelengths of 600-1100 nm. The quantum dot is fabricated via an aqueous method which forms a structure having an inner region of one composition and an outer region of a different composition, wherein the inner region contains at least a first metal and the outer region contains at least a second metal. The quantum dots may be enabled for bioconjugation and may be used in a method for tissue imaging and analyte detection.
Claims21
A quantum dot comprising:
- an inner region comprising at least a first metal sulfide, selenide or sulfide selenide, and
- an outer region having a different composition than the inner region, said outer region comprising a second metal sulfide, selenide or sulfide selenide, and
- a cap,
- said quantum dot having at least one narrow bandwidth emission in the wavelength range from of about 600 nm to about 1100 nm.
11-14. (canceled)
A method for synthesizing quantum dots comprising the steps of:
- a) reacting one or more water-soluble capping agents and a water-soluble salt of a first metal in an acidic aqueous media to form a first reaction product;
- b) subsequently adding a water-soluble sulfide to said aqueous media containing said first reaction product to form a capped metal sulfide inner region of said quantum dots;
- and
- c) subsequently adding to said aqueous media containing said capped first metal sulfide core, an amount of a water-soluble salt of a second metal in excess of a stoichiometric amount for reaction with said sulfide, to form an outer region of said quantum dot comprising a capped second metal sulfide, said quantum dots having a narrow bandwidth emission in the wavelength range of about 600 nm to about 1100 nm.
A method for synthesizing quantum dots comprising the steps of:
- a) reacting one or more water-soluble capping agents, and a water soluble sulfide and an amount of a water-soluble salt of a first metal which is less than a stoichiometric amount for reaction with said sulfide;
- and
- b) subsequently adding a water-soluble salt of a second metal and an additional amount of a water-soluble sulfide to the mixture, said quantum dots having a narrow bandwidth emission in the wave length range of about 600 nm to about 1100 nm.
Dependencies are inferred from the claim text.