Aligned single-walled carbon nanotubes array electrode: Fabrication, characterization and application

Abstract

In the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS), carboxylic group-functionalized single-walled carbon nanotubes (SWNTs) were assembled vertically on the glassy carbon electrode using ethylenediamine as linking agent to fabricate an aligned electrode (SWNTE). The morphological characteristic was studied with atomic force microscope (AFM) and its electrochemical property was investigated using K 3[Fe(CN) 6] as probe. ssDNA had a sensitive voltammetric response at the SWNTE and the oxidative peak potentials of guanine base and adenine base were 0.608 V and 0.896 V, respectively. Under the optimal conditions, the DPV peak current of guanine base vs. the concentration of ssDNA was linear in the range of 5.4 μg/L–10.8 mg/L with a detection limit of 1 μg/L (S/N = 3).