Development of electrochemical sensors responding to biologically active substances

包括离子选择性电极在内的电化学传感器的开发和应用一直是研究的热点。本研究以磷酸酯为离子载体，研制了新型有机铵离子选择膜电极。例如，己基铵离子选择性电极的构建使用三（2-乙基己基）磷酸盐（TEHP）作为离子载体和邻苯二甲酸二辛酯作为膜溶剂在聚（氯乙烯）膜基质。该电极在2**10 μ M至1**10 μ M的浓度范围内对己基铵表现出近能斯特响应<-4><-1>，斜率为57 mV/浓度十倍。检测下限为2**10 μ <-5>M，与先前报道的由胺离子载体（杯[6]芳烃类似物）之一制成的电极的检测下限相当。用核磁共振氢谱证实了磷酸酯与己铵的相互作用，并应用离子选择性电极测定了血清中游离药物的浓度。例如，使用丙吡胺膜电极原位测定血清中的游离丙吡胺水平。电位滴定法是有利的，因为血清中药物的游离浓度可以在没有样品制备的情况下测定。用电位滴定法测得的游离丙吡胺浓度与荧光偏振免疫法测得的游离丙吡胺浓度的线性相关系数为0.996。其他结果可参见本报告后面所述的参考文献。

The development and application of electrochemical sensors including ion-selective electrode continue to be an area of focues. In this study, we developed new organic ammonium ion-selective membrane elctrodes using phosphate esters as ionophores. For example, a hexylammonium ion-selective electrode was constructed using tris (2-ethylhexyl) phosphate (TEHP) as the ionophore and dioctyl phthalate as a membrane solvent in a poly (vinyl chloride) membrane matrix. The electrode exhibited a near-Nernstian response to hexylammonium in the concentration range from 2**10^<-4> to 1**10^<-1> M with a slope of 57 mV per concentration decade. The lower limit of detection was 2**10^<-5> M,was comparable to that of the electrode made from one of the amine ionophore, a calix [6] arene analog, reported previously. The interaction between the phosphate ester and hexylammonium was confirmed by ^1H-NMR spectroscopy.We also appliied ion-selective electrodes to monitor free drug levels in blood serum. For example, free disopyramide levels in serum were determined in situ using a disopyramide membrane electrode. The potentiometric method is advantageous because the free concentration of the drug in serum can be determined without sample preparation. The free disopyramide concentrations determined by potentiometry compared with those obtained by fluorescence polarization immunoassay afforded a linear correlation coefficient of 0.996.We described here only two results. Other results can be seen through references described in the back of this report.