Polymeric ionic liquid functionalized MWCNTs as efficient electrochemical interface for biomolecules simultaneous determination

Abstract

A thermal-initiation-free radical (polymeric ionic liquids (PIL)) reaction (multi-walled carbon nanotube (MWCNT)) was involved to form polymeric ionic liquids (PIL) layer on multi-walled carbon nanotube (MWCNT), which was designed as an efficient electrode modifier for simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The peak separation of AA–DA, DA–UA and AA–UA was 200mV, 120mV and 320mV, respectively, accompanied by 5.9, 5.3 and 3.7 folds current for AA, DA and UA compared to the pristine-MWCNTs/GCE. The positive imidazole-functional groups along the PIL chains were supposed to be responsible for the oxidation separation of these biomolecules. Selectively and sensitively simultaneous determination of AA, DA and UA was successfully accomplished by differential pulse voltammetry, displaying a linear response from 3.0 to 1500μM, 10.0 to 600μM and 2.0 to 60μM for each biomolecule with a detection limit (S/N=3) of 1.65μM, 2.01μM and 0.46μM, respectively. The present study not only provides functionalized MWCNTs with desirable interfacial performances, but also highlights the great potential of these functionalized tubular nanomaterials in the fields of electrocatalysis and sensing applications.