Diels−Alder Reaction for the Selective Immobilization of Protein to Electroactive Self-Assembled Monolayers

Abstract

where It is the peak current at time t, Io is the initial peak current and If is the residual nonfaradaic current. The excellent fit of the experimental data to this equation indicates that the Q groups are sufficiently isolated on the monolayer that the reactivity is independent of the extent of reaction. We next repeated this experiment with concentrations of cp ranging from 0.76 to 58 mM and in all cases found that the loss in peak current was described well by an exponential decay and that the reaction always proceeded to completion. The pseudo-first-order rate constants increased linearly with the concentration of diene: the slope of the best-fit line (Figure 3, inset) provided a second-order rate constant of kDA ) 0.26 M -1 s -1 , after adjustment for the fraction of time that Q was present. It is striking that this interfacial reaction is kinetically well-behaved. 8