In order to improve the efficiency of disease diagnosis and environmental monitoring, it is desirable to detect the concentration of proteins and metal ions simultaneously, since the current popular diagnostic platform can only detect proteins or metal ions independently. In this work, we developed a colorimetric microfluidic paper-based analytical device (µPAD) for simultaneous determination of protein (bovine serum albumin, BSA) and metal ions [Fe(III) and Ni(II)]. The µPAD consisted of one central zone, ten reaction zones and ten detection zones in one device, in which reaction solutions were effectively optimized for different types of chromogenic reactions. Fe(III), Ni(II) and BSA can be easily identified by the colored products, and their concentrations are in good accordance with color depth based on the established standard curves. The detection limits are 0.1 mM for Fe(III), 0.5 mM for Ni(II) and 1µM for BSA, respectively. Best of all, we demonstrated the efficiency of the µPAD with accurate detection of Fe(III), Ni (II) and BSA from river water samples within 15 minutes. The µPAD detection is efficient, instrument-free, and easy-to-use, holding great potential for simultaneous detection of cross type analytes in numerous diagnostic fields.

为了提高疾病诊断和环境监测的效率，需要同时检测蛋白质和金属离子的浓度，因为目前流行的诊断平台只能独立检测蛋白质或金属离子。在这项工作中，我们开发了一种比色微流控纸基分析装置 (µPAD)，用于同时测定蛋白质（牛血清白蛋白，BSA）和金属离子 [Fe(III) 和 Ni(II)]。µPAD 由一个中心区、十个反应区和十个检测区组成，在一个设备中，其中反应溶液针对不同类型的显色反应进行了有效优化。Fe(III)、Ni(II) 和 BSA 可以很容易地通过有色产品识别，它们的浓度与建立的标准曲线的颜色深度非常吻合。Fe(III) 的检测限为 0.1 mM，Ni(II) 的检测限为 0.5 mM，BSA 的检测限为 1µM。最重要的是，我们展示了 µPAD 的效率，可在 15 分钟内准确检测河水样品中的 Fe(III)、Ni (II) 和 BSA。µPAD 检测高效、无需仪器且易于使用，在众多诊断领域中同时检测交叉类型分析物具有巨大潜力。