Synthesis of fluorescent metal nanoclusters

1. A method for preparing fluorescent nanoclusters, comprising:

preparing a buffered aqueous solution of HAuCl 4 and either ascorbic acid or Chitosan under suitable conditions whereby fluorescent gold nanoclusters are produced.

2. A method for preparing fluorescent metal nanoclusters, comprising:

mixing a solution of a metal precursor and a polypeptide under conditions suitable to convert at least some of the metal precursor to fluorescent metal nanoclusters,

the metal precursor selected from a silver precursor or a gold precursor,

wherein the polypeptide comprises a β-hairpin through a d(Y)P, NG, d(P)G, d(T)V “turning” sequence.

3. A method for preparing fluorescent metal nanoclusters, comprising:

mixing a solution of a metal precursor and a polypeptide under conditions suitable to convert at least some of the metal precursor to fluorescent metal nanoclusters,

the metal precursor selected from a silver precursor or a gold precursor,

wherein the polypeptide comprises an amidated C-terminus.

4. A method for preparing fluorescent metal nanoclusters, comprising:

mixing a solution of a metal precursor and a polypeptide under conditions suitable to convert at least some of the metal precursor to fluorescent metal nanoclusters,

the metal precursor selected from a silver precursor or a gold precursor,

wherein the polypeptide is chosen from an amino acid sequence set forth in SEQ ID NO: 1 and SEQ ID NO: 20.

5. The method of claim 4 , further comprising separating the fluorescent metal nanoclusters from the polypeptide.

6. A method for preparing fluorescent metal nanoclusters comprising:

mixing a solution of a metal precursor and a polypeptide under conditions suitable to convert at least some of the metal precursor to fluorescent metal nanoclusters, the metal precursor selected from a silver precursor or a gold precursor,

wherein the polypeptide comprises a bacteriophage-displayed polypeptide and wherein the method further comprises selecting a polypeptide for binding to a noble metal by displaying the polypeptide on a bacteriophage,

wherein the bacteriophage-displayed polypeptide is chosen from an amino acid sequence set forth in SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, and SEQ ID NO: 19.

7. A method of preparing fluorescent metal nanoclusters, comprising:

mixing a two-phase liquid system comprising an aqueous phase and an organic phase, the aqueous portion comprising a biocompatible reducing agent and a polypeptide template, the organic portion comprising metal precursor, the metal chosen from gold and silver,

separating the aqueous phase from the organic phase after mixing the two-phase liquid system;

heating the aqueous solution; and

separating the template from the nanoclusters.