Panta Yogendra M, Liu Jing, Cheney Marcos A, Joo Sang W, Qian Shizhi
Department of Mechanical & Industrial Engineering, Youngstown State University, Youngstown, OH 44555, USA.
J Colloid Interface Sci. 2009 May 15;333(2):485-90. doi: 10.1016/j.jcis.2009.02.026. Epub 2009 Mar 17.
A high-precision technique that can detect mercury (II) ions down to 1 fM concentration in aqueous solutions is introduced. The technique combines the conventional electrochemical method, surface plasmon resonance (SPR), and magnetohydrodynamic (MHD) convection. Mercury ions are electroplated onto a gold SPR sensing surface, and then detected quantitatively by applying a potential scan with cyclic voltammetry. Both the SPR angular shift and the electrochemical current signal are recorded for identification and quantification of the mercury ions. The detection sensitivity is further enhanced by applying an MHD convection in the presence of a magnetic field, which does not require any moving parts intruding into the aqueous solution. The technique thus has a great advantage for small detection volume. In the presence of supporting electrolytes, 1 mM nitric acid and 10 mM potassium nitrate, Hg(2+) ionic solutions with concentrations ranging from 1 fM to 1 microM are tested under different magnetic flux densities of B=0, 0.27, 0.53, and 0.71 T. The experimental results demonstrate that the stripping signals of the 1 fM to 1 microM Hg(2+) ions are enhanced by 10-60% with the flux density B=0.71 T.
介绍了一种高精度技术，该技术能够检测水溶液中低至1 fM浓度的汞（II）离子。该技术结合了传统电化学方法、表面等离子体共振（SPR）和磁流体动力学（MHD）对流。汞离子被电镀到金SPR传感表面上，然后通过循环伏安法施加电位扫描进行定量检测。记录SPR角位移和电化学电流信号，用于汞离子的识别和定量。通过在磁场存在下施加MHD对流进一步提高了检测灵敏度，这不需要任何侵入水溶液的移动部件。因此，该技术对于小检测体积具有很大优势。在存在支持电解质（1 mM硝酸和10 mM硝酸钾）的情况下，在B = 0、0.27、0.53和0.71 T的不同磁通密度下测试了浓度范围为1 fM至1 μM的Hg(2+)离子溶液。实验结果表明，在磁通密度B = 0.71 T时，1 fM至1 μM Hg(2+)离子的溶出信号增强了10 - 60%。
