Direct electrochemistry of hemoglobin adsorbed on self-assembled monolayers with different head groups or chain length

• 1、School of Chemistry and Chemical Engineering, Sun Yat-Sen University

Abstract：The electrochemical behaviors of Hb on self-assembled monolayers (SAMs) of 3-mercaptopropanoic acid (MPA), 3-propanethiol (PT), cysteamine hydrochloride (cys), and ω-carboxyl alkanethiols with different alkyl chain length (n) were examined. A quasi-reversible redox process was observed when Hb was adsorbed on the MPA-modified electrode with reduced and oxidized peak potentials of -289 and -147 mV, respectively. The peak to peak separation (ΔE) was 142 mV. The electrochemical behaviors of Hb adsorbed onto ω-carboxyl alkanethiols SAMs with different alkyl chain length were also investigated. When n was 1, Hb revealed a weak current response and a large ΔE. When n were 2 and 5, the electron transfer constant (ks) were 0.49 s-1and 0.47 s-1, respectively. As elongating the alkyl chain length to 10, the redox properties of Hb underwent an irreversible process. The current work was expected to be useful for manipulating the interfacial properties of modified electrodes to adapt the DET pathway of Hb.

Keywords： Electrochemistry hemoglobin self-assembled monolayer direct electron transfer