Multiplexed Detection Of Fe3+, Cobalamin And Folate Using Fluorescent Nanoprobe-Based Microarrays And A Smartphone

This work reports on a smartphone-based quantitative POCT system which consists of a paper-based microarray chip, a homemade LEGO dark-box, and a smartphone installed with custom-designed FChip-APP, for on-site quantitation of Fe3+, Vitamin 12 (VB12), and folic acid (FA). Collection and automatic analysis of fluorescence turn-off response of three kinds of fluorescent nanoprobes which are coated onto filter papers by a smartphone-based device is the principle behind this study. The POCT system exhibits good analytical performance for multiplexed analysis of Fe3+, VB12 and FA with a wide linear range (Fe3+, 1.0-14.0 mu g mL(-1) (R-2 = 0.983); VB12, 1.35-40.0 mu g mL(-1) (R-2 = 0.991); FA, 2.0-26.0 mu g mL(-1) (R-2 = 0.994)) and low detection limit (Fe3+, 0.35 mu g mL(-1); VB12, 0.47 mu g mL(-1); FA, 0.56 mu g mL(-1)). The cost and weight of the whole system are similar to$220 and similar to 600 g per set, highlighting its cost-effectiveness and portability. The simple operation procedures and user-friendly interface of the FChip-APP validate the ease-of-use feature of the reported system. This versatile smartphone-based quantitative POCT system provides a cost-effective and easy-of-use method for screening the context-specific causes of anemia and thus its effective interventions in the future, especially in resource-limited areas.