Surface plasmon resonance measurement of pyridoxal kinase-pyridoxamine binding on self-assembled monolayer

Pyridoxamine-modified surface was prepared from self-assembly of pyridoxamine-linked 11-mercapto-undecan-1-one (PMU), which is synthesized via the chemistry of EDC/NHS activating 11-mercapto-undecanoic acid to link with pyridoxamine, on gold surface for the study of interaction between pyridoxamine and pyridoxal kinase (PK). This interaction was monitored by a low-cost red light-emitting-diode-based surface plasmon resonance technique. Addition of either 11-mercapto-undecan-1-ol (MU) or 1-dodecanethiol (DDT) to PMU for generating a mixed film can improve the performance of the monolayer of PMU for PK binding. Mixture of PMU and DDT in the mole ratio as low as 1:5 can achieve a significant enhancement (at least 89%) to the responses of PK binding. © 2002 Elsevier Science B.V. All rights reserved.