Zhang, X.; Sun, G.; Hovestädt, M.; Syritski, V.; Esser, N.; Volkmer, R.; Janietz, S.; Rappich, R.; Hinrichs, K.: A new strategy for the preparation of maleimide-functionalised gold surfaces. Electrochemistry Communications 12 (2010), p. 1403-1406

We have developed and investigated a new route to functionalise Au surfaces using maleimide groups. This functionalisation has been performed by grafting aminophenyl (AP) via an electrochemical reduction of 4-aminophenyldiazonium salt in acetonitrile solution and the subsequent chemical binding of N-(2-carboxyethyl) maleimide (NCEM). The resulting maleimide functionalised surface was interacted with a cysteine-modified peptide. The grafting of AP was monitored by the occurrence of NH2 and aryl ring vibrations, whereas the binding of the NCEM led to a strong and sharp peak because of the C═O stretching mode. The immobilisation of the peptide was identified by the appearance of the amide I band. Half of the maleimide surface groups reacted with the peptide because of steric hindrance. The charge efficiency for the AP layer formation was about 45% at a thickness of about 6–8 nm.