Here we demonstrate a nanofluidic device for the label‐free detection of phosphoprotein (PPn) analytes. To achieve this goal, a metal ion chelator, i.e., the 4‐[bis(2‐pyridylmethyl)aminomethyl]aniline (DPA–NH2) compound is synthesized. Single asymmetric nanofluidic channels are fabricated in polyethylene terephthalate (PET) membranes. Then the chelator (DPA–NH2) molecules are immobilized on the nanochannel surface followed by the zinc ion complexation to afford DPA–Zn2+ chelates which act as ligand moieties for the specific binding of phosphoproteins. The success of chemical reaction and biomolecular recognition process occurring in confined geometry is monitored from the changes in electrical readout of the nanochannel. The designed nanofluidic sensor has the ability to sensitively and specifically detect lower concentrations (≥1 nM) of phosphoprotein (albumin and α‐casein) in the surrounding environment as evidenced from the significant decrease in ion current flowing through the nanochannels. While, dephosphoproteins such as lysozyme and dephospho‐α‐casein even at higher concentration (˃1 µM) could not induce any significant change in the transmembrane ion flux. This indicated the sensitivity and specificity of the proposed nanofluidic sensor towards PPn proteins. In this context, we believe that metal affinity‐based nanofluidic sensor would readily be used to differentiate in between phosphoproteins and dephosphoproteins

中文翻译：

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用单个锌纳米螯合物修饰的纳米流体二极管检测磷蛋白。

在这里，我们演示了一种用于无标记检测磷蛋白（PPn）分析物的纳米流体装置。为了实现这一目标，合成了一种金属离子螯合剂，即4- [双（2-吡啶基甲基）氨基甲基]苯胺（DPA-NH2）化合物。在聚对苯二甲酸乙二醇酯（PET）膜中制造单个非对称纳米流体通道。然后将螯合剂（DPA-NH2）分子固定在纳米通道表面，然后进行锌离子络合，以提供DPA-Zn2 +螯合物，其充当磷蛋白的特异性结合的配体部分。从纳米通道的电读出的变化来监测在有限的几何形状中发生的化学反应和生物分子识别过程的成功。设计的纳米流体传感器具有灵敏和特异性地检测周围环境中较低浓度（≥1nM）的磷蛋白（白蛋白和α-酪蛋白）的能力，流过纳米通道的离子电流显着降低证明了这一点。而溶菌酶和脱磷酸α-酪蛋白等脱磷蛋白即使浓度较高（˃1µM）也不会引起跨膜离子通量的任何显着变化。这表明拟议的纳米流体传感器对PPn蛋白的敏感性和特异性。在这种情况下，我们认为基于金属亲和力的纳米流体传感器将很容易用于区分磷蛋白和脱磷蛋白 甚至更高浓度（de1 µM）的溶菌酶和脱磷酸α-酪蛋白等脱磷蛋白也不会引起跨膜离子通量的任何显着变化。这表明拟议的纳米流体传感器对PPn蛋白的敏感性和特异性。在这种情况下，我们认为基于金属亲和力的纳米流体传感器将很容易用于区分磷蛋白和脱磷蛋白 甚至更高浓度（de1 µM）的溶菌酶和脱磷酸α-酪蛋白等脱磷蛋白也不会引起跨膜离子通量的任何显着变化。这表明拟议的纳米流体传感器对PPn蛋白的敏感性和特异性。在这种情况下，我们认为基于金属亲和力的纳米流体传感器将很容易用于区分磷蛋白和脱磷蛋白