电化学检测有利于重金属镉的快速、灵敏测定。然而,检测灵敏度有待进一步提高,和一个便携式的,现场检测需要低成本设备。在这里,开发了一种原位铋修饰的预阳极氧化丝网印刷碳电极(SPCE),用于方波阳极溶出伏安法(SWASV)测定Cd2。原位铋修饰增强了Cd2+的富集,并与预阳极氧化一起提高了电极的电子转移速率,从而提高检测灵敏度。电极改性方法结合了预阳极氧化和原位铋沉积,这是非常容易和有效的。此外,自制的PSoCStat恒电位仪与搅拌装置相结合,用于便携式和低成本的电化学检测。经过全面优化,所开发的方法可以达到3分钟的测试时间,检测限为3.55μg/L,线性范围为5-100μg/L,水和大米样品中Cd2的回收率为91.7-107.1%。因此,我们的方法对快速,敏感和现场测定食品样品中的Cd2。
Electrochemical detection is favorable for the rapid and sensitive determination of heavy metal cadmium. However, the detection sensitivity needs to be further improved, and a portable, low-cost device is needed for on-site detection. Herein, an in-situ bismuth modified pre-anodized screen-printed carbon electrode (SPCE) was developed for Cd2+ determination by square wave anodic stripping voltammetry (SWASV). The in-situ bismuth modification enhances the enrichment of Cd2+, and together with pre-anodization improve the electron transfer rate of electrode, thus enhancing the detection sensitivity. The electrode modification method combines pre-anodization and in-situ bismuth deposition, which is very easy and effective. Furthermore, a self-made PSoC Stat potentiostat coupled with a stirring device was fabricated for portable and low-cost electrochemical detection. After comprehensive optimization, the developed method can reach a testing time of 3 min, a detection limit of 3.55 μg/L, a linear range of 5-100 μg/L, and a recovery rate of 91.7-107.1% in water and rice samples for Cd2+ determination. Therefore, our method holds great promise for the rapid, sensitive and on-site determination of Cd2+ in food samples.