Hydrophilic gold nanoparticles stabilized with tris(2-aminoethyl)amine: Preparation and characterization

The synthesis of Au nanoparticles through the reduction of HAuCl4 with sodium borohydride in a mixture of ethanol and isopropanol in the presence of tris(2-aminoethyl)amine is presented. The resulting powder preparation is a mixture of primary particles with the average diameter of golden cores 3.2 ± 0.6 nm, and secondary particles that were formed as a result of agglomeration of the primary ones and have core diameter up to 20 nm. The Au content of the preparation is 1.94% because Au nanoparticles have voluminous protective shells composed of the adducts of tris(2-aminoethyl)amine, acetone and boric acid, formed due to hydrogen bonding. The preparation is hydrophilic and allows one to obtain colloid solutions in water and polar solvents like acetone, isopropanol, dimethylsulphoxide, and in chloroform under ultrasonic treatment.