Direct detection of Pb in urine and Cd, Pb, Cu, and Ag in natural waters using electrochemical sensors immobilized with DMSA functionalized magnetic nanoparticles
Direct detection of Pb in urine and Cd, Pb, Cu, and Ag in natural waters using electrochemical sensors immobilized with DMSA functionalized magnetic nanoparticles
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DOI：
10.1039/b711199a
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发表时间：
2008-01-01
期刊：
影响因子：
4.2
通讯作者：
Timchalk, Charles
中科院分区：
文献类型：
--
作者：
Yantasee, Wassana;Hongsirikarn, Kitiya;Timchalk, Charles
尿液是公认的最佳非侵入性基质之一，用于生物监测暴露于广泛的外源性物质，包括有毒金属。由于蛋白质竞争和电极污染，尿液中金属离子的检测一直存在问题。为了直接，简单，和现场部署的监测尿铅，电化学传感器采用超顺磁性氧化铁（Fe 3 O 4）纳米粒子与二巯基丁二酸（DMSA）的表面功能化已被开发。金属检测包括在磁性或电磁电极处从样品溶液中快速收集分散的金属结合的纳米颗粒，然后在酸性介质中进行金属的溶出伏安法。传感器进行了评估作为一个函数的溶液pH值，结合亲和力的铅DMSA -Fe 3 O 4，每样品体积的纳米粒子的比例，预浓缩时间，和铅的浓度。研究了DMSA-Fe_3 O_4与尿中铅组分的竞争结合对传感器响应的影响。在含有25体积%的样品中预浓缩90 s后在0.1g L ~（-1）的DMSA-Fe_3 O_4溶液中，该传感器可检测到铅的背景浓度（0.5 ppb），并在0至50 ppb的Pb范围内产生线性响应，具有良好的重现性（30 ppb Pb的7次测量的% RSD为5.3），该传感器还可以同时检测背景水平（< 1 ppb）的Cd，Pb，Cu，河流和海水中的Ag。
Urine is universally recognized as one of the best non-invasive matrices for biomonitoring exposure to a broad range of xenobiotics, including toxic metals. Detection of metal ions in urine has been problematic due to the protein competition and electrode fouling. For direct, simple, and field-deployable monitoring of urinary Pb, electrochemical sensors employing superparamagnetic iron oxide (Fe3O4) nanoparticles with a surface functionalization of dimercaptosuccinic acid (DMSA) has been developed. The metal detection involves rapid collection of dispersed metal-bound nanoparticles from a sample solution at a magnetic or electromagnetic electrode, followed by the stripping voltammetry of the metal in acidic medium. The sensors were evaluated as a function of solution pH, the binding affinity of Pb to DMSA - Fe3O4, the ratio of nanoparticles per sample volume, preconcentration time, and Pb concentrations. The effect of binding competitions between the DMSA - Fe3O4 and urine constituents for Pb on the sensor responses was studied. After 90 s of preconcentration in samples containing 25 vol.% of rat urine and 0.1 g L-1 of DMSA - Fe3O4, the sensor could detect background level of Pb (0.5 ppb) and yielded linear responses from 0 to 50 ppb of Pb, excellent reproducibility (% RSD of 5.3 for seven measurements of 30 ppb Pb), and Pb concentrations comparable to those measured by ICP-MS. The sensor could also simultaneously detect background levels (< 1 ppb) of Cd, Pb, Cu, and Ag in river and seawater.