Digital microfluidics (DMF) is a versatile lab-on-a-chip platform that allows integration with several types of sensors and detection techniques, including colorimetric sensors. Here, we propose, for the first time, the integration of DMF chips into a mini studio containing a 3D-printed holder with previously fixed UV-LEDs to promote sample degradation on the chip surface before a complete analytical procedure involving reagent mixture, colorimetric reaction, and detection through a webcam integrated on the equipment. As a proof-of-concept, the feasibility of the integrated system was successfully through the indirect analysis of S-nitrosocysteine (CySNO) in biological samples. For this purpose, UV-LEDs were explored to perform the photolytic cleavage of CySNO, thus generating nitrite and subproducts directly on DMF chip. Nitrite was then colorimetrically detected based on a modified Griess reaction, in which reagents were prepared through a programable movement of droplets on DMF devices. The assembling and the experimental parameters were optimized, and the proposed integration exhibited a satisfactory correlation with the results acquired using a desktop scanner. Under the optimal experimental conditions, the obtained CySNO degradation to nitrite was 96%. Considering the analytical parameters, the proposed approach revealed linear behavior in the CySNO concentration range between 12.5 and 400 μmol L⁻¹ and a limit of detection equal to 2.8 μmol L⁻¹. Synthetic serum and human plasma samples were successfully analyzed, and the achieved results did not statistically differ from the data recorded by spectrophotometry at the confidence level of 95%, thus indicating the huge potential of the integration between DMF and mini studio to promote complete analysis of lowmolecular weight compounds.

数字微流体 (DMF) 是一种多功能的芯片实验室平台，可以集成多种类型的传感器和检测技术，包括比色传感器。在这里，我们首次建议将 DMF 芯片集成到一个迷你工作室中，该工作室包含一个 3D 打印的支架和预先固定的 UV-LED，以在涉及试剂混合、比色反应的完整分析程序之前促进芯片表面的样品降解，并通过设备上集成的网络摄像头进行检测。作为概念验证，通过对生物样品中 S-亚硝基半胱氨酸 (CySNO) 的间接分析，成功证明了集成系统的可行性。为此，探索了 UV-LED 对 CySNO 进行光解裂解，从而直接在 DMF 芯片上产生亚硝酸盐和副产物。然后基于改进的 Griess 反应对亚硝酸盐进行比色检测，其中通过液滴在 DMF 设备上的可编程运动来制备试剂。组装和实验参数得到优化，所提出的集成与使用桌面扫描仪获得的结果表现出令人满意的相关性。在最佳实验条件下，所得CySNO对亚硝酸盐的降解率为96%。考虑到分析参数，所提出的方法揭示了 CySNO 浓度范围在 12.5 和 400 μmol·L 之间的线性行为 并且建议的集成与使用桌面扫描仪获得的结果显示出令人满意的相关性。在最佳实验条件下，所得CySNO对亚硝酸盐的降解率为96%。考虑到分析参数，所提出的方法揭示了 CySNO 浓度范围在 12.5 和 400 μmol·L 之间的线性行为 并且建议的集成与使用桌面扫描仪获得的结果显示出令人满意的相关性。在最佳实验条件下，所得CySNO对亚硝酸盐的降解率为96%。考虑到分析参数，所提出的方法揭示了 CySNO 浓度范围在 12.5 和 400 μmol·L 之间的线性行为^-1且检测限等于2.8 μmol L ^-1。成功分析了合成血清和人血浆样本，所取得的结果与分光光度法记录的数据在 95% 的置信度下没有统计学差异，这表明 DMF 和 mini studio 之间的集成在促进完整分析方面的巨大潜力低分子化合物。