Analysis of total polyphenols in wines by FIA with highly stable amperometric detection using carbon nanotube-modified electrodes

► Glassy carbon electrodes modified with a carbon nanotube-polyethyleneimine layer. ► Nanotube layer gives excellent stability in the amperometric detection of polyphenols. ► Selective detection of easily-oxidizable and total polyphenol groups in wine samples. ► Remarkable correlation with conventional spectrophotometric assays.