In view of the charge characteristic of cationic polymers, herein, we put forward a sensitive and unique colorimetric sensor array strategy for discrimination of proteins. We used gold nanoparticles (AuNPs) as colorimetric probes and three nonspecific DNA strands (15A, 15C, and 15T) as nonspecific receptors. Upon the addition of the proteins, the diverse interactions between DNA and proteins result in the difference in the number of the remaining DNA strands. As we know, cationic polymer, such as poly(diallyldimethylammonium chloride) (PDDA), can interact with DNA and AuNPs with negative charges. Therefore, these remaining DNA strands can interact with PDDA. Superfluous PDDA molecules bind to AuNPs, leading to different AuNP aggregation. On the basis of this phenomenon, linear discriminant analysis (LDA) is employed to quantitatively discriminate the colorimetric responses (A₆₂₀/A₅₂₀) of proteins. At the 20 nM level, 11 proteins were completely distinguished with 100% accuracy. Remarkably, the feasibility of the method was confirmed by the discrimination of proteins in serum.

中文翻译：

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使用比色传感器阵列基于阳离子聚合物诱导的金纳米粒子聚集的蛋白质区分。

考虑到阳离子聚合物的电荷特性，在本文中，我们提出了一种敏感而独特的比色传感器阵列策略来区分蛋白质。我们使用金纳米颗粒（AuNPs）作为比色探针，并使用三个非特异性DNA链（15A，15C和15T）作为非特异性受体。添加蛋白质后，DNA与蛋白质之间的各种相互作用会导致剩余DNA链数量的差异。众所周知，阳离子聚合物，例如聚二烯丙基二甲基氯化铵（PDDA），可以与带负电荷的DNA和AuNPs相互作用。因此，这些剩余的DNA链可以与PDDA相互作用。多余的PDDA分子与AuNPs结合，导致不同的AuNP聚集。基于这种现象，A ₆₂₀ / A ₅₂₀）的蛋白质。在20 nM的水平上，可以100％的准确度完全分辨出11种蛋白质。值得注意的是，该方法的可行性通过区分血清中的蛋白质得到了证实。