Metal nanoclusters and uses thereof
Provided herein are metal nanoclusters, having a high absorption to volume ratio, and uses of the same, such as in generating singlet oxygen, or in protecting surfaces from high intensity light.
1. A conjugate comprising a metal nanocluster having at least a portion of the surface of the metal nanocluster modified with a moiety having a structure -X-Lk-Lg;
wherein
the metal nanocluster comprises Au 144 , Ag 32 , or a combination thereof;
Lk is C 1-50 alkylene, wherein the carbon backbone optionally has one or more heteroatoms selected from O, NH, and S;
X is a functional group capable of attaching to the metal nanocluster surface; and
Lg is a ligand selected from the group consisting of a peptide, a protein, an oligonucleotide, a fluorophore, and a chromophore.
2. The conjugate of claim 1 , wherein X comprises an alcohol, an ether, a thiol, a phosphate, a phosphonate, phosphinate, or a carboxylate.
3. The conjugate of claim 1 , wherein the metal nanocluster is Au 144 .
4. The conjugate of claim 1 , wherein Lg is a two-photon chromophore.
5. The conjugate of claim 1 , wherein Lg is a fluorophore.
6. A composition comprising the conjugate of claim 1 in a liquid.
7. A composition comprising the conjugate of claim 1 in the form of a coating or a film.
8. The composition of claim 7 , wherein the film comprises a polymer selected from the group consisting of polyvinylpyrrolidone, polyvinyl alcohol, poly-methyl methacrylate, polystyrene, polyethylene oxide, polyethylene glycol, and a mixture thereof.
9. The composition of claim 7 , further comprising a photosensitive additive.
10. The conjugate of claim 1 , wherein the metal nanocluster exhibits an absorption to volume ratio of at least 10 7 m −1 under linear or non-linear excitation, has an excited state longer than 10 psec, and exhibits no plasmon resonance.