Bio-Inspired Electrochemical Detection of Nitric Oxide Promoted by Coordinating the Histamine-Iron Phthalocyanine Catalytic Center on Microelectrode

Abstract

Biomimetic structures to fabricate bioelectronic interfaces that allow sensors to electrically communicate with electrodes have potential applications in the development of biosensors. Herein, inspired by the structure feature of nitric oxide (NO) sensory protein, we constructed a biomimetically catalytic center, the histamine coordinated iron phthalocyanine (FePc), for efficient and sensitive detection of NO. In specific, NO is recognized by axial tethered FePc, and the oxidative signal of NO on FePc is converted into output signal through electrocatalytic oxidation. Based on the fabricated catalytic structure on the carbon fiber electrode, on one hand, the macrocyclic π system of FePc enabled a rapid redox process, which facilitates electron transfer, thereby greatly improving sensitivity. On the other hand, by coordination with histamine on the electrode surface, FePc can enhance the electrochemical oxidation activity toward NO and promote catalytic detection, which have been revealed by electrochemical characterizations and density functional theory theoretical calculations. The designed electrochemical microsensor exhibits a low limit of detection (0.03 nM) and shows a wide detection range (0.1 nM−2 μM). In addition, the electrochemical microsensor has been successfully used for real-time monitoring of NO release by live cells. So, this work shows a new strategy for the design of bioinspired electrochemical microsensors that may provide a potential analytical tool for tracing biological signal molecules with enzyme-free biomimetically catalytic centers.

The control of nitric oxide dynamics and interaction with substituted zinc-phthalocyanines

“…The substituents may also influence the potential of the carbon electrodes to which they are adsorbed for NO detection and in the case of decreased potential may improve NO selectivity. 54 This property should apply whatever the central metal atom and independently of whether the M-PC is linked to a microelectrode 30,55 or not.…”