Surface engineered nanoparticles for improved surface enhanced Raman scattering applications and method for preparing same

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.