College of Chemistry and Molecular Engineering, Nanjing Tech University , Nanjing 210009, China.
Department of Microbiology and Immunology, School of Medicine, University of Nevada , Reno, Nevada 89557, United States.
Anal Chem. 2017 May 2;89(9):5024-5029. doi: 10.1021/acs.analchem.7b00383. Epub 2017 Apr 13.
Here we describe a new and sensitive flow electrochemical detection system that employs a novel flow-field shaped solid electrode (FFSSE). The system was constructed with a 3D-printed thin-layer flow cell (TLFC) and a flat screen-printed FFSSE with USB connection. This interface facilitates continuous flow accumulation square-wave anodic stripping voltammetry (ASV). The flow distribution in the working space of TLFC was simulated using the finite element method (FEM) and the shape and configuration of electrodes were optimized accordingly. We demonstrated the electrochemical determination of Pb using this newly designed TLFC-FFSSE detection system without removal of oxygen from samples. This TLFC-FFSSE based system showed an attractive stripping voltammetric performance compared to a traditional ASV based method. A linear range for detection of Pb was found to be 0.5-100 μg/L (0.5 to 100 ppb) and a detection limit of 0.2 μg/L (0.2 ppb) was achieved in the presence of bismuth as codeposition metal. The system was further applied to detect Pb in biological broths of methane fermentation. The electrochemical detection results were consistent with that obtained from atomic fluorescence spectroscopy (AFS) analysis and the average recovery was found to be 95.5-106.5% using a standard addition method. This new flow electrochemical detection system showed better sensitivity and reproducibility compared to a traditional ASV based method. Such a system offers great potential for on-site and real-time detection of heavy metals where compact, inexpensive, robust, and low-volume analysis is required.
在这里，我们描述了一种新的和敏感的流动电化学检测系统，该系统采用了新颖的流场成型固体电极（FFSSE）。该系统由 3D 打印的薄层流池（TLFC）和带有 USB 连接的平面印刷 FFSSE 构建而成。该接口便于连续流动积累方波阳极溶出伏安法（ASV）。使用有限元方法（FEM）模拟了 TLFC 工作空间中的流动分布，并相应地优化了电极的形状和配置。我们使用新设计的 TLFC-FFSSE 检测系统演示了无需从样品中去除氧气的 Pb 的电化学测定。与传统的基于 ASV 的方法相比，这种基于 TLFC-FFSSE 的系统表现出了有吸引力的溶出伏安性能。发现 Pb 的检测线性范围为 0.5-100μg/L（0.5 至 100 ppb），在存在铋作为共沉积金属的情况下，检测限为 0.2μg/L（0.2 ppb）。该系统进一步应用于检测甲烷发酵生物培养基中的 Pb。电化学检测结果与原子荧光光谱法（AFS）分析获得的结果一致，使用标准添加法的平均回收率为 95.5-106.5%。与传统的基于 ASV 的方法相比，这种新的流动电化学检测系统具有更高的灵敏度和重现性。这种系统在需要紧凑、廉价、坚固和小体积分析的现场和实时重金属检测方面具有很大的潜力。
