Electropolymerized toluidine blue O functionalized ordered mesoporous carbon-ionic liquid gel-modified electrode and its low-potential detection of NADH

A novel gel was developed based on the polymerization of a composite containing toluidine blue O (TBO) functionalized ordered mesoporous carbon (OMC) by a π–π stacking interaction and ionic liquid (IL). The poly (toluidine blue O) (PTBO)-OMC-IL composite film distributes almost homogeneously with unique structure on the surface of substrate. The PTBO-OMC-IL gel modified glass carbon (GC) electrode displays high conductivity investigated by electrochemical method. Electrochemical studies suggest that the PTBO-OMC-IL gel/GC electrode provide a positively synergistic effect among PTBO, OMC and IL on the electrochemical oxidation of NADH. Under a low applied potential of −0.034 V, NADH could be linearly detected from 1.0 μmol L−1 up to 6.0 mmol L−1 with a low detection limit of 0.4 μmol L−1 (S/N = 3) and fast response time of 2 s. So the PTBO-OMC-IL gel modified electrode may be used as electrochemical transducers and has potential application for designing a variety of NAD+-dependent electrochemical biosensors.