# US 8,465,721 B2 · Biosynthesis of nanoparticles

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- Number: US 8,465,721 B2
- Document ID: US8465721B2
- Status: Granted
- Kind: B2
- Application number: 13/310,335
- Filed: 2011-12-02
- Published: 2012-06-28
- Granted: 2013-06-18
- Earliest claimed: 2010-12-03
- Assignees: Queen's University at Kingston
- Applicants: Chad D. Edwards; Daniel D. Lefebvre
- Inventors: Chad D. Edwards; Daniel D. Lefebvre
- Web page: https://patentgrep.com/patent/US8465721B2

## CPC

- C01B 19/007: {Tellurides or selenides of metals (C01B19/002 takes precedence)}
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- B82Y 40/00: Manufacture or treatment of nanostructures
- C01G 1/12: Sulfides
- C01G 9/00: Compounds of zinc
- C01G 11/02: Sulfides
- C12N 1/12: Unicellular algae; Culture media therefor (as new plants A01H13/00)
- C12N 1/14: Fungi (culture of mushrooms A01G18/00; as new plants A01H15/00); Culture media therefor
- C12N 1/20: Bacteria; Culture media therefor
- C12P 3/00: Preparation of elements or inorganic compounds except carbon dioxide {(recovery of carbon dioxides as by-products C12F3/02)}
- C01P 2002/84: by UV- or VIS- data
- C01P 2004/64: Nanometer sized, i.e. from 1-100 nanometer
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- C12N: MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA (microbiological testing media C12Q1/00)
- C12P: FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE {(brewing of beer C12C; producing vinegar C12J; producing specific peptides or proteins C07K; producing enzymes C12N9/00; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; measuring or testing processes involving enzymes or microorganisms C12Q; measuring or testing processes involving nucleic acid amplification reactions C12Q1/6844; fermentation processes to form a food composition, A21 or A23; compounds in general, see the relevant compound class, e.g. C01, C07)}
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

This invention provides a method of biosynthesizing nanoparticles and quantum dots. The method may comprise culturing photosynthetic cells and/or fungal cells of a multicellular fungus in a culture medium comprising one or more species of metal in ionic or non-ionic form; and one or more counter elements to the one or more species of metal, or one or more compound comprising one or more counter elements to the one or more species of metal; wherein the cells biosynthesize nanoparticles and quantum dots incorporating the metal. The invention also provides biosynthesized nanoparticles and quantum dots.

## Claims

### Claim 1

A method of biosynthesizing a nanoparticle; comprising:
culturing photosynthetic cells under conditions that cause the cells to perform photosynthesis in a culture medium comprising:
(i) one or more elements of Periodic Table groups 15 and 16, or one or more compounds comprising one or more elements of Periodic Table groups 15 and 16; and
(ii) one or more species of metal in ionic or non-ionic form;
wherein the cells biosynthesize nanoparticles incorporating the metal.

### Claim 2 (depends on 1)

The method of claim 1, wherein a concentration of the one or more elements of Periodic Table groups 15 and 16, or the one or more compounds comprising one or more elements of Periodic Table groups 15 and 16, is elevated relative to a concentration in a standard culture medium.

### Claim 3 (depends on 2)

The method of claim 2, wherein the concentration is 2× to 100× times, or greater than 100×, the concentration in the standard culture medium.

### Claim 4 (depends on 1)

The method of claim 1, wherein the conditions that cause the cells to perform photosynthesis include culture medium substantially without a carbon or energy source.

### Claim 5 (depends on 1)

The method of claim 1, further comprising recovering nanoparticles from the cells.

### Claim 6 (depends on 5)

The method of claim 5, wherein recovering nanoparticles from the photosynthetic cells comprises:
acidifying the culture medium to induce cellular flocculation; and
centrifuging the obtained cellular flocculent to concentrate the nanoparticles.

### Claim 7 (depends on 1)

The method of claim 1, wherein the nanoparticles include quantum dots.

### Claim 8 (depends on 1)

The method of claim 1, wherein the metal ions are derived from one or more elements of Periodic Table groups 11 to 14.

### Claim 9 (depends on 1)

The method of claim 1, wherein the photosynthetic cells are prokaryotic cells.

### Claim 10 (depends on 1)

The method of claim 1, wherein the photosynthetic cells are eukaryotic cells.

### Claim 11 (depends on 1)

The method of claim 1, wherein the photosynthetic cells are a combination of prokaryotic cells and eukaryotic cells.

### Claim 12 (depends on 1)

The method of claim 1, comprising manipulating one or more variables during the biosynthesis, wherein the variables are selected from:
concentration of one or more metals;
ratio of two or more metals;
concentration of the one or more elements of Periodic Table groups 15 and 16, or the one or more compounds comprising one or more elements of Periodic Table groups 15 and 16;
duration of exposure of the cells to the one or more metals;
oxygen and/or carbon dioxide availability to the cells;
pH of the medium;
temperature and/or pressure of the bioreactor;
one or more constituents of the culture medium; and
light intensity;
wherein manipulation of one more variables determines a characteristic of the nanoparticle.

### Claim 13 (depends on 12)

The method of claim 12, wherein the characteristic is size of the nanoparticle.

### Claim 14 (depends on 13)

The method of claim 13, wherein the nanoparticle is a quantum dot.

### Claim 15

A method of biosynthesizing a layered nanoparticle; comprising:
(a) culturing photosynthetic cells under conditions that cause the cells to perform photosynthesis in a culture medium comprising:
(i) one or more elements of Periodic Table groups 15 and 16, or one or more compounds comprising one or more elements of Periodic Table groups 15 and 16; and
(ii) one or more species of metal in ionic or non-ionic form;
(b) subsequently culturing the cells under conditions that cause the cells to perform photosynthesis in a culture medium comprising:
(iii) one or more elements of Periodic Table groups 15 and 16, or one or more compounds comprising one or more elements of Periodic Table groups 15 and 16; and
(iv) one or more species of metal in ionic or non-ionic form, wherein at least one species of metal is different from that used in (ii);
wherein the cells biosynthesize nanoparticles incorporating the metal of (ii) in a first layer and the metal of (iv) in a second layer.

### Claim 16 (depends on 15)

The method of claim 15, further comprising repeating step (b) a selected number of times with different metal so as to biosynthesize a nanoparticle with a selected number of layers, each layer comprising a selected one or more species of metal.

### Claim 17 (depends on 15)

The method of claim 15, wherein the nanoparticle is a quantum dot.

### Claim 18 (depends on 1)

A nanoparticle produced according to the method of claim 1.

### Claim 19 (depends on 18)

The nanoparticle of claim 18, wherein the nanoparticle comprises at least one metal selected from copper, zinc, cadmium, indium, and gallium.

### Claim 20 (depends on 1)

A quantum dot produced according to the method of claim 1.

### Claim 21 (depends on 20)

The quantum dot of claim 20, wherein the quantum dot comprises at least one metal selected from copper, zinc, cadmium, indium, and gallium.