Prasad Bhim Bali, Sharma Piyush Sindhu, Lakshmi Dhana
Analytical Division, Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India.
J Chromatogr A. 2007 Nov 30;1173(1-2):18-26. doi: 10.1016/j.chroma.2007.10.024. Epub 2007 Oct 13.
The development of an easy-to-use, rapid, robust and inexpensive technique is required which can measure the basal concentration of uric acid (UA) lower than 1.0 x 10(-7)M ( approximately 0.017 mgL(-1)) in biological samples to attend the problem of hypouricemia. In the present work an artificial receptor for UA, silica gel-bonded molecularly imprinted polymer (MIP), was used as a sorbent for molecularly imprinted solid-phase extraction (MISPE) in column chromatography. The use of a sensor based on a MIP-modified hanging mercury drop electrode (HMDE), as reported from our laboratory, could estimate UA with detection limit as low as 0.024 mgL(-1) under the optimized conditions of differential pulse, cathodic stripping voltammetric (DPCSV) measurement. However, in the current investigation, with the use of the combination of MISPE followed by detection with a MIP-based HMDE sensor, the minimum detectable concentration could go down to 0.0008 mgL(-1) (RSD=0.63%, S/N=3). The same MIP receptor for both MISPE and the corresponding sensor was able to enhance the preconcentration of analyte substantially so as to attain the desired level of sensitivity; and that to without any interference (cross-reactivity) from other structurally related analogues including the major interferent like ascorbic acid prevalent in the aqueous environment of biological samples.
需要开发一种易于使用、快速、稳健且廉价的技术，该技术能够测量生物样品中低于1.0×10⁻⁷M（约0.017mgL⁻¹）的尿酸（UA）基础浓度，以解决低尿酸血症问题。在本工作中，一种用于UA的人工受体，硅胶键合分子印迹聚合物（MIP），被用作柱色谱中分子印迹固相萃取（MISPE）的吸附剂。如我们实验室所报道的，使用基于MIP修饰悬汞滴电极（HMDE）的传感器，在差分脉冲阴极溶出伏安法（DPCSV）测量的优化条件下，可估计UA，检测限低至0.024mgL⁻¹。然而，在当前研究中，通过使用MISPE结合基于MIP的HMDE传感器进行检测，最低可检测浓度可降至0.0008mgL⁻¹（相对标准偏差=0.63%，信噪比=3）。用于MISPE和相应传感器的相同MIP受体能够显著提高分析物的预富集程度，从而达到所需的灵敏度水平；并且不会受到其他结构相关类似物的任何干扰（交叉反应），包括生物样品水性环境中普遍存在的主要干扰物如抗坏血酸。
