Self-assembled multilayer thin films of nanometer-sized gold particles linked with organic dithiols have been prepared on glass, indium tin oxide, and gold substrates. The gold particles within these structures retain their integrity and no sintering occurs as demonstrated by their optical absorbance, ellipsometry, and potential modulated transmission and reflectance spectroscopy. The optical response to electrochemical charge injection into the outermost layer of gold particles is completely different from that of bulk gold electrodes, and it is concluded that the particles have to be regarded as discrete, immobilized quantum-dots.