A new type of hydrogel-coated paper sensor was developed for the semiquantitative and naked-eye detection of Cu²⁺ ions with high selectivity and good regenerability. The paper sensor showed a continuous color change from colorless to blue, resulting in semiquantitative naked-eye detection. Furthermore, similar to the classical pH test paper, a standard colorimetric card was used in the visual detection of Cu²⁺ ions by identifying the RGB value of the hydrogel-coated paper sensor. The application of the standard colorimetric card has greatly shortened the detection time and reduced the cost of detection, providing a new strategy for the naked-eye and semiquantitative detection of heavy-metal ions in water samples.

中文翻译：

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标准比色卡通过水凝胶涂布纸传感器对Cu（II）进行半定量肉眼检测

开发了一种新型的水凝胶涂层纸传感器，用于半定量和肉眼检测Cu ²⁺离子，具有高选择性和良好的可再生性。纸传感器显示出从无色到蓝色的连续颜色变化，从而实现了半定量肉眼检测。此外，类似于经典的pH试纸，通过识别水凝胶涂覆的纸传感器的RGB值，将标准比色卡用于视觉检测Cu ²⁺离子。标准比色卡的应用大大缩短了检测时间，降低了检测成本，为肉眼和半定量检测水样中的重金属离子提供了新的策略。