Corrole-based conjugated monomer as a new functional molecule for designing affinity interfaces

Abstract

Here, a novel corrole-based conjugated monomer, pyrrole-corrole (Py-Cor) was synthesized to design a functional interface for affinity interactions, which dramatically increases the sensor signal towards model proteins of immunoglobulin G, albumin, and lysozyme. First, the monomer was characterized by nuclear magnetic resonance spectroscopy (NMR), high-resolution mass spectrometry (HRMS), and Fourier transform infrared spectroscopy (FTIR). Then, the functional monomer was electrochemically polymerized on a gold electrode in the presence of pristine pyrrole as a comonomer. The polymeric film was characterized via both chemical and electrochemical routes by conducting cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and Raman spectroscopy measurements. Due to the metal chelating feature of the corrole ring, copper(II) [Cu(II)] ions were utilized to design a metal chelate affinity film for demonstrating their interaction capability with various proteins. Cu(II) immobilization process was achieved by voltammetry whereas the metal chelate affinity studies were performed using EIS measurements. In order to show the effect of the presence of Cu(II) ions, the sensor performance in terms of the protein recognition capabilities was carried out both in the presence/absence of Cu(II) ions. The presence of Cu(II) ions in the structure significantly improved the recognition performance of the interfaces as well as enhanced the resulted semi-circuit diameters.