A disposable non-enzymatic histamine sensor based on the nafion-coated copper phosphate electrodes for estimation of fish freshness

Histamine is an important index for the estimation of allergic reaction and food freshness. This study develops a single-step dipping and coating method to fast produce an electrochemical histamine sensor based on a nafion-coated copper phosphate (Cu3(PO4)2)-dominated electrode. The flake-like Cu3(PO4)2 nanostructures can be fast formed on Cu-electrodeposited screen printed carbon electrodes (SPCEs) within 20 min. Moreover, the 1% nafion-coated Cu3(PO4)2/SPCEs presented good selectivity for the detection of histamine in the pH 8.5 solution. The nafion/Cu3(PO4)2/SPCEs can be integrated with a flow-injection device for the detection of histamine with a good correlation coefficient (R = 0.999) in the range of 5-500 ppm. The calculated limit of detection was 3.0 ppm. Moreover, the histamine concentration of 45 h-rotten fish samples detected by the nafion/Cu3(PO4)2/SPCEs had a less than 10% deviation from that measured by the commercialized liquid chromatography-mass spectroscopy. The nafion/Cu3(PO4)2/SPCEs have great promise for estimating the freshness of fish meat without expensive separation equipment and labor-intensive labeling procedures.