Blood electrolyte measurements play important roles in clinical diagnostics. Optical ion sensors as simple and elegant as a mercury thermometer are in high demand. We present here an analytical method to quantify potassium ions in undiluted human blood and plasma by measuring the distance or the rate of the color propagation. The sensor was composed of K⁺-selective nanospheres embedded in an agarose hydrogel where mass transport was diffusion controlled. The sensor’s color-changing rate and the distance of color propagation depended linearly on the logarithm of K⁺ activity. A theoretical model was established and fully supported the experimental findings. This work lays the foundation of a new family of optical ion sensors for direct determination of common blood electrolytes.

中文翻译：

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非平衡扩散控制离子选择性光学传感器测定血钾

血电解质的测量在临床诊断中起着重要的作用。像水银温度计一样简单，优雅的光学离子传感器的需求量很大。我们在这里提出一种分析方法，通过测量距离或颜色传播的速度来量化未稀释的人类血液和血浆中的钾离子。该传感器由嵌入在琼脂糖水凝胶中的K ^+-选择性纳米球组成，在该琼脂糖水凝胶中，质量传输受到扩散控制。传感器的变色率和颜色传播距离线性地取决于K ⁺活度的对数。建立了理论模型并完全支持实验结果。这项工作为直接测定常见血液电解质的光学离子传感器新系列奠定了基础。