In situ FTIR studies of an oxidation product from protein adsorption at the platinum electrode

The subtractively normalized interfacial Fourier transform infrared spectro scopy (SNIFTIRS) has been used to examine an oxidation product from adsorpt ion of the enzyme, ribonuclease A, at the platinum electrode. At potentials of 600 mV (SCE), a negative going peak due to the formation of the oxidati on product CO2 was clearly visible with both s- and p-polarized IR beams. T his gives evidence that adsorption of the protein occurs through the carbox ylate groups of the acidic residues of the protein at anodic potentials wit h subsequent oxidation occurring by a decarboxylation mechanism. (C) 2000 A cademic Press.