Patent ID: 7608461

Claim:
A method for preparing SERS gold nanoparticles, the method comprising the steps of: (a) forming a first emulsion comprising: (i) forming a first oil phase mixture comprising a bulk oil phase and a surfactant mixture comprising sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and phosphatidylcholine (PTC); (ii) forming a first dilute aqueous solution consisting essentially of water and a gold salt; (iii) adding the first dilute aqueous solution into the first oil phase mixture; and (iv) agitating the first oil phase mixture to provide the first emulsion; (b) forming a second emulsion comprising: (i) forming a second oil phase mixture comprising a bulk oil phase and a surfactant mixture comprising AOT and PTC; (ii) forming a second dilute aqueous solution comprising a reducing agent selected from the group consisting of reducing agent selected from the group of ascorbic acid, urea, dimethylamine borane (DMAB), sulfur dioxide or β-mercaptoethanol; (iii) adding the second dilute aqueous solution into the second oil phase mixture; and (iv) agitating the second oil phase mixture to provide the second emulsion; (c) adding the second emulsion to the first emulsion to provide an emulsion mixture; (d) stirring the emulsion mixture to initiate a reduction reaction between the reducing agent and the gold salt solution to provide a precipitate dispersed in the emulsion mixture; and (e) separating the precipitate from the emulsion mixture, thereby providing a plurality of gold nanoparticles, wherein the gold nanoparticles comprise a nanometer scale roughened surface structure.