Jason Shing-Yip Lau

Synthesis, crystal structures, electrochemical and protein-binding properties of ferrocene–indole conjugates

This paper describes the synthesis, characterisation and electrochemical properties of three redox-active ferrocene–indole compounds, N-(ferrocenylmethylenyl)tryptamine (Fc–CHNC2H4-indole) (Fc1), N-(ferrocenylmethyl)tryptamine (Fc–CH2NHC2H4-indole) (Fc2) and indole-3-(N-(6-(N-ferrocenylmethyl)aminohexyl))carboxamide (Fc–CH2NHC6H12NHCO-indole) (Fc3). The X-ray crystal structures of Fc1 and Fc2 have been investigated. The recognition of the redox-active ferrocene–indole compounds Fc2 and Fc3 by indole-binding proteins including bovine serum albumin and tryptophanase has been studied by electrochemical and luminescence titrations and enzyme inhibition assays.

Specific labelling of sulfhydryl-containing biomolecules with redox-active N-(ferrocenyl)iodoacetamide

The synthesis, characterisation, X-ray crystal structure and electrochemical properties of a new redox-active labelling reagent, N-(ferrocenyl)iodoacetamide (Fc-IAA), are reported. This compound exhibits a reversible ferrocenium/ferrocene couple at ca. +0.345 V vs. SCE at a sweep rate of 100 mV s−1 in CH3CN at 298 K, and two irreversible reduction waves at ca. −1.324 and −2.048 V, attributable to the reduction of the iodoacetamide group. Since the iodoacetamide moiety can react specifically with the sulfhydryl group, Fc-IAA has been coupled to various biomolecules including a sulfhydryl-modified oligonucleotide, cysteine, glutathione and sulfhydryl-modified bovine serum albumin. The electrochemical properties of the bioconjugates have also been investigated.