Paper-based devices have been very much in the foreground of analytical science recently. This work innovatively proposed a fluorescent paper-based sensor (FPS) constructed on a hybrid polydimethylsiloxane (PDMS)/paper platform where cellulose papers functionalized with carbon dots (CDs) as fluorophores by Schiff base chemistry were loaded on the grooves array of a designed PDMS plate. As a proof of concept, the performance of FPS was investigated with folic acid (FA) as the target analyte. Under optimal conditions, FPS enabled a rapid fluorescence quenching response to FA via inner filter effect in a wide range of 1-300 μmol L-1 with the limit of detection of 0.28 μmol L-1. The feasibility of FPS was further verified by the detection of FA in orange juice and urine samples with satisfactory results. The covalent modification of CDs on paper endowed the FPS with good assay reproducibility and stability. Interestingly, FPS achieved a more sensitive assay of FA than the conventional strategy, by which the same CDs were directly used to detect FA in a solution-based system. The FPS illuminated a novel strategy for construction of reliable and sensitive assays based on paper-based devices. It is of paramount importance for its practical application in biosensing and clinical diagnosis. Graphical abstract.

中文翻译：

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基于碳点的荧光纸基传感器，用于检测叶酸。

纸基设备近来已成为分析科学的前沿。这项工作创新性地提出了一种基于荧光纸的传感器（FPS），该传感器构建在混合的聚二甲基硅氧烷（PDMS）/纸平台上，其中通过席夫碱化学法将以碳点（CD）作为荧光团功能化的纤维素纸加载到设计的PDMS的凹槽阵列上盘子。作为概念证明，以叶酸（FA）为目标分析物研究了FPS的性能。在最佳条件下，FPS通过内部过滤器效应在1-300μmolL-1的宽范围内实现了对FA的快速荧光猝灭响应，检出限为0.28μmolL-1。通过检测橙汁和尿液样品中的FA进一步验证了FPS的可行性，结果令人满意。CD在纸上的共价修饰赋予FPS良好的测定重现性和稳定性。有趣的是，与传统策略相比，FPS实现了对FA的更灵敏的测定，通过传统方法，相同的CD被直接用于检测基于溶液的系统中的FA。FPS提出了一种新颖的策略，用于基于纸质设备构建可靠且灵敏的检测方法。它对于其在生物传感和临床诊断中的实际应用至关重要。图形概要。它对于其在生物传感和临床诊断中的实际应用至关重要。图形概要。它对于其在生物传感和临床诊断中的实际应用至关重要。图形概要。