Fluorescent ink compositions comprising functionalized fluorescent nanocrystals

1. An image formed by a method comprising applying onto a substrate a fluorescent ink composition, wherein the composition comprises functionalized fluorescent semiconductor nanocrystals, an aqueous-based ink carrier comprising water or a water-based solution, and a binder, wherein the method provides an image on a substrate for subsequent identification.

2. An image formed by the method according to claim 1 , wherein the image comprises a security mark.

3. An image formed by the method according to claim 1 , wherein the fluorescent ink composition further comprises an additional component selected from the group consisting of a biocide, a surfactant, a defoamer, a corrosion inhibitor, and a combination thereof.

4. An image formed by the method according to claim 1 , wherein the method further comprises applying onto the substrate a plurality of fluorescent ink compositions wherein each of the plurality of fluorescent ink compositions is capable of fluorescing a specific color, thereby providing an image which is multicolor upon subsequent identification.

5. An image formed by the method according to claim 1 , wherein the functionalized fluorescent nanocrystals are operably bound to the binder, thereby forming a cross-linked fluorescent ink composition.

6. A substrate having printed thereon an image according to claim 1 .

7. A substrate having printed thereon an image according to claim 2 .

8. A substrate having printed thereon an image according to claim 3 .

9. A substrate having printed thereon an image according to claim 4 .

10. A substrate having printed thereon an image according to claim 5 .