Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand; Nanomaterials Science, Sensors & Catalysis for Problem-Based Projects, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand.
Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand; Nanomaterials Science, Sensors & Catalysis for Problem-Based Projects, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand.
Talanta. 2021 Apr 1;225:122077. doi: 10.1016/j.talanta.2020.122077. Epub 2021 Jan 2.
We report a novel three-dimensional microfluidic paper-based analytical device (3D-μPAD) with colorimetric detection, using Mn-ZnS quantum dot embedded molecularly imprinted polymer (Mn-ZnS QD-MIP), for selective glyphosate determination in whole grain samples. Detection is based on the catalytic activity of Mn-ZnS QD-MIP in the HO oxidation of ABTS. Glyphosate imprinted polymer is successfully synthesized on the Mn-ZnS QD surface using a poly (N-isopropylacrylamide) (NIPAM) and N, N'-Methylenebisacrylamide (MBA) as the functional monomers. The catalytic activity depends on binding or non-binding of glyphosate molecules on the synthetic recognition sites of the Mn-ZnS QD-MIP. Glyphosate selectively binds to the cavities embedded on the Mn-ZnS QD surface, and subsequently turns-off or inhibits the ABTS oxidation and color change to light green. The change of reaction color from dark green to light green depends on the concentration of glyphosate. We report, for the first time, using the relatively new penguard enamel colour to create a hydrophobic barrier. The foldable 3D-μPAD comprises three layers (top/center/bottom), named as the detection zone, immobilized Mn-ZnS QD-MIP disc, and sample loading. Assay on the 3D-μPAD can determine glyphosate by ImageJ detection, over an operating range of 0.005-50 μg mL and with a detection limit of 0.002 μg mL. Our 3D-μPAD exhibits high accuracy, with a 0.4% (intra-day) and 0.7% (inter-day) relative difference from the certified CRM value. Moreover, the fabricated 3D-μPAD provides good reproducibility (1.7% RSD for ten devices). The developed 3D-μPAD was successfully applied to determine the glyphosate concentration in whole grain samples and shows great promise as an alternative highly selective and sensitive colorimetric method. The 3D-μPAD is well suited to food-quality control and onsite environmental-monitoring applications, without sophisticated instrumentation.
我们报告了一种新型的基于三维微流控纸的分析装置（3D-μPAD），具有比色检测功能，使用嵌入 Mn-ZnS 量子点的分子印迹聚合物（Mn-ZnS QD-MIP），用于选择性测定全谷物样品中的草甘膦。检测基于 Mn-ZnS QD-MIP 在 ABTS 的 HO 氧化中的催化活性。Mn-ZnS QD 表面上成功合成了草甘膦印迹聚合物，使用聚（N-异丙基丙烯酰胺）（NIPAM）和 N，N'-亚甲基双丙烯酰胺（MBA）作为功能单体。催化活性取决于 Mn-ZnS QD-MIP 合成识别位点上草甘膦分子的结合或非结合。草甘膦选择性地结合到嵌入在 Mn-ZnS QD 表面上的空腔中，随后关闭或抑制 ABTS 氧化和颜色变为浅绿色。反应颜色从深绿色变为浅绿色的变化取决于草甘膦的浓度。我们首次报道使用相对较新的彭古德珐琅色创建疏油屏障。可折叠的 3D-μPAD 由三层（顶部/中心/底部）组成，分别称为检测区、固定化 Mn-ZnS QD-MIP 圆盘和样品加载区。通过 ImageJ 检测，3D-μPAD 可以在 0.005-50μgmL 的工作范围内测定草甘膦，检测限为 0.002μgmL。我们的 3D-μPAD 表现出高精度，与认证 CRM 值的相对差异为 0.4%（日内）和 0.7%（日间）。此外，制造的 3D-μPAD 具有良好的重现性（十个器件的 RSD 为 1.7%）。开发的 3D-μPAD 成功用于测定全谷物样品中的草甘膦浓度，并且作为一种替代的高选择性和灵敏的比色方法具有很大的潜力。3D-μPAD 非常适合食品质量控制和现场环境监测应用，无需复杂的仪器。
