Semiconductor nanoparticle capping agents
Embodiments of the invention involve semiconductor nanoparticle capping ligands, their production and use. Ligands may have the formula with m ranging from approximately 8 to approximately 45. An embodiment provides a method of forming a compound of the formula including the steps of providing a first starting material comprising poly(ethyleneglycol) and reacting the first starting material with a second starting material comprising a functional group for chelating to the surface of a nanoparticle to thereby form the compound.
1. A method for producing capped nanoparticles comprising capping at least one nanoparticle with a compound of formula XO—(CH 2 CH 2 O) m —Y, wherein X is selected from the group consisting of H, CH 3 , and —CH 2 CO 2 H, Y is selected from the group consisting of p-toluene sulphonate, carboxyl, —CH 2 CO 2 H, -PhCO 2 H, —SiPh 2 t Bu, phenyl, —CH 2 Ph and phthalamide, and m is an integer, and wherein the capping comprises exchanging at least some existing ligands coating the nanoparticle for the compound of formula XO—(CH 2 CH 2 ) m —Y.
2. The method of claim 1 , wherein m ranges from 8 to 45.
3. The method of claim 1 , wherein the at least one nanoparticle comprises at least one semiconductor material.
4. The method of claim 3 , wherein the semiconductor material is selected from one or more of the group of semiconductor materials consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, InP, InAs, InSb, AlP, Al 2 S 3 , AlAs, AISb, GaN, GaP, GaAs, GaSb, PbS, PbSe, Si, and Ge.
5. The method of claim 1 , wherein the existing ligands are lipophilic surface binding ligands.
6. The method of claim 1 , wherein the existing ligands are selected from the group consisting of myristic acid, hexadecylamine and trioctylphosphineoxide.
7. The method of claim 1 , wherein the capping increases the stability of the nanoparticle in aqueous media.
8. A method for producing capped nanoparticles comprising capping at least one nanoparticle with a compound of formula XO—(CH 2 CH 2 O) m —Y wherein X is selected from the group consisting of H, CH 3 , and —CH 2 CO 2 H, Y is selected from the group consisting of p-toluene sulphonate, carboxyl, —CH 2 CO 2 H, -PhCO 2 H, —SiPh 2 t Bu, phenyl, —CH 2 Ph and phthalamide, and m is an integer, wherein capping comprises interchelating the compound of formula XO—(CH 2 CH 2 O) m —Y into existing ligands coating the nanoparticle.
9. The method of claim 8 , wherein the existing ligands are lipophilic surface binding ligands.
10. The method of claim 8 , wherein the existing ligands are selected from the group consisting of myristic acid, hexadecylamine and trioctylphosphineoxide.
11. A method of producing capped nanoparticles, the method comprising: forming a compound of the formula
XO—(CH 2 CH 2 O) m —Y
wherein X is selected from the group consisting of H, CH 3 , and —CH 2 CO 2 H, Y is selected from the group consisting of p-toluene sulphonate, carboxyl, —CH 2 CO 2 H, -PhCO 2 H, —SiPh 2 t Bu, phenyl, —CH 2 Ph and phthalamide and m is an integer, by:
providing a first starting material comprising poly(ethyleneglycol) and a terminal hydroxyl group;
reacting the first starting material with a second starting material comprising a leaving group and a functional group for chelating to the surface of a nanoparticle thereby detaching the leaving group and forming the compound; and
capping at least one nanoparticle with a compound of formula XO—(CH 2 CH 2 O) m —Y.
12. The method of claim 11 , wherein the leaving group is p-toluene sulfonate.
13. Nanoparticles capped with a compound of formula
XO—(CH 2 CH 2 O) m —Y
wherein X is selected from the group consisting of H, CH 3 , and —CH 2 CO 2 H, Y is selected from the group consisting of p-toluene sulphonate, carboxyl, —CH 2 CO 2 H, -PhCO 2 H, —SiPh 2 t Bu, phenyl, —CH 2 Ph and phthalamide and m is an integer, and wherein at least one of the nanoparticles comprises a semiconductor material selected from one or more of the group of semiconductor materials consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, InP, InAs, InSb, AlP, Al 2 S 3 , AlAs, AlSb, GaN, GaP, GaAs, GaSb, PbS, PbSe, Si, and Ge.