The simultaneous synthesis of gold nanoparticles in both water and chloroform by the spontaneous reduction of aqueous chloroaurate ions by a diamine-containing oxyethylene linkage that partitions in both phases is demonstrated. The oxidation of the diamine consequent to reduction of the gold ions results in the polymerization of the diamine and formation of a polymeric coating around the gold nanoparticles. The gold nanoparticles are uniform in size ranging between 3 and 6 nm. The nanoparticles capped with the polymer may be stored as a powder and readily redispersed in nonpolar organic solvents and water, indicating that the surface of the polymer capping the nanoparticles is significantly different in both cases.

Electroporation: A BTX 600 electro cell manipulator was used to deliver PEG-QDs to HeLa cells. Electroporation parameters were varied using several solutions (phosphate-buffered saline, Krebs Ringers Buffer, Dulbecco's Modified Eagles' Medium, and HEPESbuffered (HEPESÐ4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid) isotonic glucose solution), charging voltages (100±500 V), and pulse lengths (0.5±20 ms). Optimal intracellular delivery without extensive cell death (greater than 50 % viability) occurred in PBS with a single 100±200 V, 1±5 ms pulse. Approximately 10 6 cells were suspended in 400 lL of DMEM with 250 lg mL ±1 QDs. The electroporation charge was applied, and, after 10 min, the cells were pelleted to remove the QD solution, and then plated on coverslips. All steps were performed at 4 C to prevent endocytosis of QDs.

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