Amperometric Sensor Based on Carbon Nanotubes and Polycations for the Determination of Vitamin C

Detection of vitamin C (VC) is necessary because of its wide use in chemical, biological, and pharmaceutical engineering. Here, we describe a sensing system for the determination of VC. Instead of a bare glassy carbon electrode (GCE), a prepared multi-walled carbon nanotube-polycation-GCE was used to detect VC in samples with higher sensitivity, better repeatability, and with a lower detection limit. Under the optimal conditions, the obtained sensor presented a linear response to VC in the range of 1–100 μM with a detection limit of 500 nM. The proposed electrode also successfully detected VC concentrations in real samples.