Huang Genin Gary, Yang Jyisy
Department of Chemistry, National Chung-Hsing University, Taichung 402, Taiwan.
Biosens Bioelectron. 2005 Sep 15;21(3):408-18. doi: 10.1016/j.bios.2004.11.001. Epub 2004 Dec 8.
In this paper, a new and simple evanescent wave type of infrared biosensor is described for the selective detection of tyrosine in biological fluids. This sensor is based on the formation of copper complexes between the sensing phase and tyrosine. To demonstrate that this principle was applicable to the selective detection of tyrosine, a proline-modified sensing phase was synthesized on the surface of the internal reflection elements. This sensing phase was saturated with copper ions to allow it to interact with tyrosine units in aqueous solution through the formation of stable proline-Cu2+-tyrosine complexes. Tyrosine exhibits a unique spectral feature in its absorption band at 1515 cm-1. This band significantly differs from those of other amino acids and provides a further method for the discrimination of tyrosine. By investigating the signals from 12 amino acids, only three amino acids, each containing a phenyl group, could be sensed selectively by this sensing phase. Based on the unique absorption of tyrosine located at 1515 cm-1, tyrosine can be selectively detected. To perform quantitative analyses of tyrosine using this sensing phase, a theoretical working equation was developed and correlated with the experimental data. The analytical results indicated that the developed equations do explain and predict the detection behaviors of the proposed sensing scheme. Using the optimal conditions, the regression coefficients for standard curves of tyrosine recorded in the region of concentrations below 600 microM were higher than 0.996 under either equilibrium or non-equilibrium conditions. Detection limit of tyrosine when using this method was ca. 3 microM.
本文描述了一种新型、简单的倏逝波型红外生物传感器，用于选择性检测生物体液中的酪氨酸。该传感器基于传感相和酪氨酸之间形成铜配合物。为证明该原理适用于酪氨酸的选择性检测，在内反射元件表面合成了脯氨酸修饰的传感相。该传感相用铜离子饱和，使其能通过形成稳定的脯氨酸-Cu2+-酪氨酸配合物与水溶液中的酪氨酸单元相互作用。酪氨酸在其1515 cm-1吸收带具有独特的光谱特征。该谱带与其他氨基酸的谱带显著不同，为区分酪氨酸提供了另一种方法。通过研究12种氨基酸的信号，该传感相只能选择性地检测到三种含苯基的氨基酸。基于酪氨酸在1515 cm-1处的独特吸收，可选择性检测酪氨酸。为使用该传感相对酪氨酸进行定量分析，建立了理论工作方程并与实验数据相关联。分析结果表明，所建立的方程确实能解释和预测所提出传感方案的检测行为。在最佳条件下，在平衡或非平衡条件下，浓度低于600 microM区域记录的酪氨酸标准曲线的回归系数均高于0.996。使用该方法时酪氨酸的检测限约为3 microM。
