Peptide nanotubes/self-assembled polydopamine molecularly imprinted biochip for the impedimetric detection of human Interleukin-6

Abstract

In the study, an impedimetric biochip was designed with molecularly imprinted polydopamine (MIP(pDa)) on peptide nanotube (PNT) functionalized screen printed electrodes (SPEs) and adopted first time as a support matrix to construct the electrochemical sensor for the determination of interleukin 6 (IL-6). IL-6, which is one of the important cytokines, was used as a template molecule during the self-assembly polymerization strategy of dopamine. Dopamine acted as a functional monomer and self-polymerization occurred without any initiator, enzyme, or crosslinker. Impedimetric, spectrometric, and morphological characterization data demonstrated that MIP(pDa)/PNT provided satisfactory performance for the impedimetric diagnosis of IL-6. Analyzed IL-6 biomolecules could be detected in the range of 1-200 pg/mL due to the good correlation between the redox pair response and the logarithm of IL-6 concentration. The MIP(pDa)/PNT electrode was capable of selective binding for IL-6 with high recovery values in urine sample. The designed methodology allowed us to detect IL-6 with an effective, facile and inexpensive route that was easy to fabricate and scale-up. The coupling of MIP(pDa)/PNT with SPEs and the use of the impedimetric detection approach holds great potential to provide a new avenue for clinical diagnostics because in these systems small volumes of samples can be analyzed without the need for any pre-processing steps in short times.

Keywords: Impedimetric detection; Interleukin-6; Molecularly imprinted; Peptide nanotube; Polydopamine.