Electropolymerisation of brilliant cresyl blue and neutral red on carbon-nanotube modified electrodes in binary and ternary deep eutectic solvents

Brilliant cresyl blue (BCB) and neutral red (NR) have been electropolymerized in binary and ternary deep eutectic solvents (DES) on glassy carbon electrodes (GCE) modified with multiwalled carbon nanotubes (CNT). The influence of binary and ternary DES composition on the polymer film properties was evaluated. Cyclic voltammetry and electrochemical impedance spectroscopy were used to characterise the PBCB and PNR films. PBCB/CNT/GCE and PNR/CNT/GCE platforms with polymer formed in ternary DES led to an improvement of the electrochemical properties of the modified electrodes compared to polymer synthesised in the corresponding binary DES. The second hydrogen bond donor tuned the DES characteristics, leading to a sensor platform with higher sensitivity. The PNR/CNT/GCE prepared in different binary and ternary DES were successfully tested for ascorbate sensing and demonstrated the applicability of the sensor architectures.