# US 2021/0340438 A1 · Composite quantum dot, method for preparing the same, and method for detecting metal ion using the same

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- Number: US 2021/0340438 A1
- Document ID: US20210340438A1
- Status: Published application
- Kind: A1
- Application number: 17/145,868
- Filed: 2021-01-11
- Published: 2021-11-04
- Earliest claimed: 2020-04-30
- Assignees: National Tsing Hua University
- Applicants: National Tsing Hua University
- Inventors: Hsueh-Shih CHEN; Pin-Ju CHEN
- Web page: https://patentgrep.com/patent/US20210340438A1

## CPC

- C09K 11/025: {non-luminescent particle coatings or suspension media}
- C09K 11/0883: {Arsenides; Nitrides; Phosphides}
- C09K 11/54: containing zinc or cadmium
- C09K 11/70: containing phosphorus
- G01N 21/643: {non-biological material}
- B82Y 15/00: Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
- B82Y 20/00: Nanooptics, e.g. quantum optics or photonic crystals
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- B82Y 40/00: Manufacture or treatment of nanostructures
- G01N 2021/6439: {with indicators, stains, dyes, tags, labels, marks}
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

A composite quantum dot includes a quantum dot and a protecting unit. The quantum dot includes a dot body containing a first layer having a composition of M1A1, and a passivating unit containing a passivating metal ion and bound to the dot body. M1 is one of Zn, Sn, Pb, Cd, In, Ga, Ge, Mn, Co, Fe, Al, Mg, Ca, Sr, Ba, Ni, Ag, Ti and Cu, and A1 is one of Se, S, Te, P, As, N, I and O. The protecting unit adsorbs on the quantum dot and includes an amine compound and/or a primary ammonium salt thereof. A method for preparing the composite quantum dot and a method for detecting metal ions in an analyte aqueous solution using the composite quantum dot, as well as a passivated quantum dot and a preparation thereof, are also disclosed.

## Claims

### Claim 1

A composite quantum dot, comprising:
a quantum dot including a dot body which includes a first layer having a composition of M1A1, and a passivating unit which includes a passivating metal ion and which is bound to said dot body, wherein M1 is a metal selected from the group consisting of Zn, Sn, Pb, Cd, In, Ga, Ge, Mn, Co, Fe, Al, Mg, Ca, Sr, Ba, Ni, Ag, Ti and Cu, and A1 is an element selected from the group consisting of Se, S, Te, P, As, N, I and O; and
a protecting unit adsorbing on said quantum dot and including a primary ammonium salt of an amine compound.

### Claim 2 (depends on 1)

The composite quantum dot of claim 1, wherein said amine compound is a primary amine.

### Claim 3 (depends on 2)

The composite quantum dot of claim 2, wherein said passivating metal ion of said passivating unit is selected from the group consisting of a di-valent metal ion and a tri-valent metal ion, and said primary amine has carbon atoms ranging from 12 to 20.

### Claim 4 (depends on 3)

The composite quantum dot of claim 3, wherein said passivating metal ion is selected from the group consisting of Zn2+ ion, Cd2+ ion, Pb2+ ion, Cu2+ ion, Mn2+ ion, Fe3+ ion, Ni2+ ion, Cr3+ ion and combinations thereof, and said amine compound is oleylamine.

### Claim 5 (depends on 1)

The composite quantum dot of claim 1, where M1 is selected from the group consisting of In and Zn, and A1 is selected from the group consisting of P, Se and S.

### Claim 6 (depends on 1)

The composite quantum dot of claim 1, wherein the quantum dot further includes a second layer surrounding said first layer, and a third layer surrounding said second layer, said second layer having a composition of M1xM21-xA1yA21-y, 0<x≤1 , 0<y<1, said third layer having a composition of M1A2 or M2A2, and having a base portion and a plurality of spaced-apart protrusion portions that extend from said base portion in a direction away from said second layer, M2 being different from M1 and being selected from the group consisting of Zn, Sn, Pb, Cd, In, Ga, Ge, Mn, Co, Fe, Al, Mg, Ca, Sr, Ba, Ni, Ag, Ti and Cu, A2 being different from A1 and being an element selected from the group consisting of Se, S, Te, P, As, N, I and O.

### Claim 7 (depends on 6)

The composite quantum dot of claim 6, wherein M2 is selected from the group consisting of Zn, Sn, Pb and Cd, and A2 is selected from the group consisting of Se, S and P.

### Claim 8 (depends on 1)

A method for preparing the composite quantum dot of claim 1, comprising a step of reacting a M1-containing precursor with a A1-containing precursor in the presence of a passivating agent and a protecting agent,
wherein M1 is selected from the group consisting of Zn, Sn, Pb, Cd, In, Ga, Ge, Mn, Co, Fe, Al, Mg, Ca, Sr, Ba, Ni, Ag, Ti and Cu; A1 is an element selected from the group consisting of Se, S, Te, P, As, N, I and O; the passivating agent includes a salt of a passivating metal; and the protecting agent is an amine compound.

### Claim 9 (depends on 8)

The method of claim 8, wherein the M1-containing precursor is selected from the group consisting of a halide of M1, an acetate of M1, an oxide of M1, and combinations thereof.

### Claim 10 (depends on 8)

The method of claim 8, wherein the A1-containing precursor is selected from the group consisting of amine coordination compound, a hydride of A1 and a combination thereof.

### Claim 11 (depends on 8)

The method of claim 8, wherein the salt of the passivating metal is selected from the group consisting of a fatty acid salt of the passivating metal, an acetic acid salt of the passivating metal, a halide salt of the passivating metal, and combinations thereof.

### Claim 12 (depends on 8)

The method of claim 8, wherein the amine compound is a primary amine.

### Claim 13 (depends on 1)

A method for manufacturing a passivated composite quantum dot, comprising a step of contacting the composite quantum dot as claimed in claim 1 with an aqueous solution.

### Claim 14 (depends on 13)

The method of claim 13, wherein the aqueous solution includes a polar solvent and water, and water is present in an amount that is not greater than 50% (v/v) based on the total volume of the aqueous solution.

### Claim 15 (depends on 13)

The method of claim 13, wherein the aqueous solution includes a metal ion that is selected from the group consisting of Zn2+ ion, Cd2+ ion, and a combination thereof.

### Claim 16 (depends on 1)

A passivated composite quantum dot, which is manufactured by a method comprising a step of contacting the composite quantum dot as claimed in claim 1 with an aqueous solution, and which has a fluorescence wavelength that is different from that of a composite quantum dot as claimed in claim 1.

### Claim 17 (depends on 1)

A method for detecting metal ions in an analyte aqueous solution, comprising the steps of:
preparing a first solution that includes a plurality of the composite quantum dots as claimed in claim 1;
contacting an analyte aqueous solution with the first solution to form a second solution; and
analyzing fluorescence characteristics of the first solution and the second solution, so as to detect the metal ions in the analyte aqueous solution.

### Claim 18 (depends on 17)

The method of claim 17, wherein the analyte aqueous solution includes an amine compound.

### Claim 19 (depends on 17)

The method of claim 17, wherein each of the fluorescence characteristics of the first solution and the second solution is selected from the group consisting of a fluorescence intensity, a fluorescence wavelength, and a combination thereof.

### Claim 20 (depends on 17)

The method of claim 17, wherein the analyte aqueous solution includes a polar solvent and water, and water is present in an amount that is not greater than 50% (v/v) based on the total volume of the aqueous solution.