An electrochemical sensor based on an anti-fouling membrane for the determination of histamine in fish samples.

Electrochemical determination of histamine (HA) is quite challenging owing to the high oxidation potential and electrode fouling from HA oxide polyhistamine, which leads to poor sensitivity and unrepeatable measurement. In the present work, a simple, sensitive and repeatable electrochemical measurement of HA was developed based on a Nafion and multi-walled carbon nanotube (MWCNTs) composite membrane modified glassy carbon electrode (GCE). Compared with the bare GCE, the Nafion and MWCNT composite membrane modified electrode significantly enhanced the oxidation peak current and reduced the peak potential to 1.12 V (vs. SCE). Moreover, the characterization of the modified electrode by XPS and EIS showed that polyhistamine scarcely deposited on the composite membrane of the modified GCE, which made it possible to realize repeatable electrochemical measurement of HA. The electrochemical oxidation behavior of HA on the modified electrode was studied by differential pulse voltammetry (DPV). The oxidation peak current has linear and natural log-linear relationships with HA concentration in the range of 20-200 μmol L and 0.5-10 μmol L, respectively. The detection limit was 0.39 μmol L (S/N = 3). The modified electrode could be used to determine 100 μmol L HA ten times repeatedly; the peak currents in consecutive runs were all above 95% of the initial response. This method was also successfully applied to the determination of HA in fish samples and recoveries ranged from 98.2 to 101.2%.