Cytochrome P450 2D6 biosensor for perphenazine based on multi-walled carbon nanotube/ionic liquid and tetrathiafulvalene-tetracyanoquinodimethane salt/ionic liquid gels

•A new approach to prepare TTF–TCNQ/IL gel.•MWNT/IL gel is used as the matrix of TTF–TCNQ/IL gel.•The synergetic effect of MWNT/IL and TTF–TCNQ/IL promote the catalysis of CYP2D6.•Low detection limit for perphenazine. A cytochrome P450 2D6 (CYP2D6) biosensor was developed with the incorporation of multi-walled carbon nanotube/ionic liquid and tetrathiafulvalene-tetracyanoquinodimethane salt/ionic liquid (MWNT/IL-[TTF–TCNQ]/IL) gels. The MWNT/IL-[TTF–TCNQ]/IL gels were characterized using Fourier-transform infrared spectroscopy, ultraviolet–visible spectroscopy, and scanning electron microscopy. Utilizing the excellent stability of the MWNT/IL gel and the unique structure of the [TTF–TCNQ]/IL gel, CYP2D6 was immobilized on the screen-printed electrode with high bioactivity. Moreover, the CYP2D6 catalytic effect was highly promoted upon application of MWNT/IL-[TTF–TCNQ]/IL gels as the mediating system. The proposed MWNT/IL-[TTF–TCNQ]/IL gel-based CYP2D6 biosensor was used to detect perphenazine via voltammetry and amperometry. The calibration of perphenazine ranged from 6 × 10−8 to 1.6 × 10−5 M with a detection limit of 2.05 × 10−8 M. It is expected that the MWNT/IL-[TTF–TCNQ]/IL gel-based CYP2D6 biosensor opens new avenues for promising advances in the analysis of drugs. [Display omitted]