水凝胶波导传感器对呼吸丙酮的检测
Hydrogel Waveguide Sensors for Breath Acetone Detection

近年来，针对糖尿病的呼吸丙酮(BrAce)检测，新型化学传感器的研发层出不穷。然而，现有的传感器普遍存在以下问题：一方面，操作繁琐，且需配备复杂的样品处理装置；另一方面，要么造价昂贵，要么灵敏度不足，难以满足实际应用的需要。针对上述问题我们提出了一种基于水凝胶波导的BrAce气体传感器。该传感器利用水凝胶的三维多孔结构，高效捕获待测丙酮气体，并使其与波导内部的硫酸羟胺反应生成氢离子(H⁺)，从而引发波导内部pH值的变化。这种pH值的变化进而导致波导内部溴酚蓝吸收光谱发生改变。通过检测溴酚蓝对波导内部传输光的吸收，实现了对健康成年人的BrAce检测。实验表明，该水凝胶波导传感器能够检测出低于0.9 ppm的丙酮气体浓度，而正常人BrAce浓度在0.3~0.9 ppm，能够有效地检测出正常人体内的BrAce气体。该水凝胶波导传感器制备方法简单，成本低廉，灵敏度高，操作简单，能够有效地应对日常生活中的使用场景。
In recent years, various sensors have been developed for the detection of breath acetone (BrAce) in diabete management. However, existing sensors face signification challenges: they are often cumbersome to operate, requiring complex sample-handling devices, or tend to be either expensive or insufficiently sensitive for practical applications. To address these issues, we propose a BrAce gas sensor based on hydrogel waveguides. This sensor leverages the three-dimensional porous structure of hydrogel to efficiently capture acetone gas, which then reacts with hydroxylamine sulfate pre-doped in the waveguide to generate hydrogen ions (H⁺), thereby triggering a pH change within the waveguide. This change in pH, in turn, alters the absorption spectrum of bromophenol blue within the waveguide. By detecting changes in the absorption spectrum of bromophenol blue, we achieve a highly sensitive BrAce detection. Experimental results demonstrate that the hydrogel waveguide sensor can detect acetone concentrations lower than 0.9 ppm, while the normal BrAce in healthy individuals ranges from 0.3~0.9 ppm. This capability enables effective BrAce detection in healthy individuals. Additionally, the sensor features a simple fabricate process, low cost, high sensitivity and ease of operation, making it permits for everyday use.