In this work, a multiplexed colorimetric strategy was initiated for simultaneous and fast visualization of dyes using low-cost and easy-to-prepare indicator papers as sorbents. Response surface methodology (RSM) was employed to model statistically and optimize the process variables for dyes extraction and colorimetric assays. Multiplexed colorimetry was realized by virtue of synchronous color alignments from different dimensions of multiple dyes co-stained colorimetric cards under RSM-optimized conditions, and smartphone-based image analysis was subsequently performed from different modes to double-check the credibility of colorimetric assays. As concept-to-proof trials, simultaneous visualization of dyes in both beverages and simulated dye effluents was experimentally proved with results highly matched to HPLC or spiked amounts at RSM-predicted staining time as short as 50 s ∼3 min, giving LODs as low as 0.97 ± 0.22/0.18 ± 0.08 μg/mL (tartrazine/brilliant blue) for multiplexed colorimetry, which much lower than those obtained by single colorimetry. Since this is the first case to propose such a RSM-guided multiplexed colorimetric concept, it will provide a reference for engineering of other all-in-one devices which can realize synchronous visualization applications within limited experimental steps.

中文翻译：

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多重比色法与基于智能手机的图像分析相结合，可同时快速地可视化环境和食品样品中的染料

在这项工作中，采用了一种多重比色策略，使用低成本且易于制备的指示纸作为吸附剂，同时快速地观察染料。采用响应面法 (RSM) 进行统计建模并优化染料提取和比色测定的过程变量。在 RSM 优化的条件下，通过多种染料共染色比色卡的不同尺寸的同步颜色对齐实现了多重比色法，随后从不同模式进行基于智能手机的图像分析，以双重检查比色测定的可信度。作为从概念到证明的试验，饮料和模拟染料废水中染料的同步可视化得到了实验证明，其结果与 HPLC 高度匹配或在 RSM 预测的染色时间短至 50 秒~3 分钟的情况下加标量，使 LOD 低至多重比色法测定结果为0.97±0.22/0.18±0.08μg/mL（柠檬黄/艳蓝），远低于单一比色法得到的结果。由于这是第一个提出这种RSM引导的多重比色概念的案例，因此它将为其他一体化设备的工程设计提供参考，这些一体化设备可以在有限的实验步骤内实现同步可视化应用。