A simple method for preparing metal nanoparticle films immobilized on gold substrates is described. A variety of nanoparticle films are characterized by electrochemical infrared reflection-ab sorption spectroscopy (EC-IRAS) in which the anomalous "negative-absorbance" properties commonly observed in metal particle arrays can be completely controlled. Such "anti-absorbance" nu(CO) band components obfuscating the EC-IRAS data interpretation are associated with the complex dielectric behavior induced by metal nanoparticles aggregates. To achieve a well distributed metal nanoparticle array, the substrates were pretreated with 3-mercaptopropyltrimethoxysilane before anchoring gold, platinum or platinum-ruthenium alloy nanoparticles on the gold substrates. The prepared nanoparticle films displayed excellent electrochemical properties implying facile electronic communication through the organic glue matrix between the nanoparticle arrays and the gold substrates. Coating of the gold nanoparticle arrays with platinum via copper underpotential deposition (UPD) steps furthermore demonstrates optimal electronic response between the nanoparticle arrays and the underlying substrate. These findings will facilitate better nanoparticle analysis by electrochemical and optical spectroscopic means.