We demonstrate a facile and rapid methodology for preparation of [email protected] core-shell nanostructures on a cost-effective pencil graphite substrate. Galvanic replacement reaction was carried out for palladium modification on template electrodeposited copper nanostructures on pencil graphite substrate. The nanostructures are shown to be very stable with excellent electrocatalytic activities. Under optimised conditions, they could be used for histamine sensing at a very low oxidation potential of +0.55 V vs. Ag/AgCl. The low oxidation potential enabled sensitive and selective analysis of histamine using chronoamperometry without any interference from oxygen evolution reactions. We have demonstrated that the sensor shows excellent selectivity towards histamine even in the presence of many of the common interfering biogenic amines. The sensor exhibited a sensitivity of 0.082 $\mu$ A/$\mu$ M/cm ${}^2$ with a limit of detection as low as 3.2 $\pm$ 0.1 nM. The oxidation potential and limit of detection obtained using this sensor are much superior to the results reported so far in the literature. Practical feasibility of the developed sensor was manifested by histamine analysis in canned tuna fish samples, where the chronoamperometric estimation was also validated by conventional HPLC analysis.

我们展示了一种经济高效的铅笔石墨基底上制备[受电子邮件保护的]核-壳纳米结构的便捷方法。在铅笔状石墨基底上的模板电沉积铜纳米结构上进行了钯取代的电置换反应。纳米结构显示非常稳定，具有出色的电催化活性。在优化的条件下，它们可用于相对于Ag / AgCl的+0.55 V的极低氧化电位下的组胺感测。低氧化电位可使用计时安培法对组胺进行灵敏和选择性的分析，而不会受到氧气释放反应的干扰。我们已经证明，即使在许多常见的干扰生物胺的存在下，该传感器对组胺也具有出色的选择性。$\mu$ 一个/$\mu$ 米/厘米 ${}^{\mathrm{2个}}$ 检出限低至3.2 $\pm$0.1 nM。使用该传感器获得的氧化电位和检测极限远远优于文献中迄今报道的结果。罐装金枪鱼样品中的组胺分析表明了开发的传感器的实际可行性，同时传统的HPLC分析也验证了计时安培估计值。