Quartz crystal microbalance(QCM) and cyclic voltammetry(CV) were used to characterize the monolayer of cytochrome c(Cyt c),which was adsorbed on gold film modified with alkanethiol mixed monolayer.A direct comparison of protein surface coverages calculated from QCM and cyclic voltammetric measurements illustrates that the ratio of the electroactive Cyt c to the total surface-confined Cyt c is 34%,which suggests that the orientation is a main factor affecting the electroactivity of Cyt c.Moreover,surface plasmon resonance(SPR) measurement combined with CV "in situ" was used to investigate the conformational change of Cyt c in the redox process.Besides,Au nanoparticles(Au NPs) were adsorbed on the surface of Cyt c.The result indicates that Au NPs promote electron transfer between Cyt c and the gold electrode,and SPR result suggests Au NPs enhance SPR signal.
WANG Yan-yan JIANG Yan-xla ZHOU You-chen LI Yan-yan MA Zhi-fang SUN Shi-gang
