In this study, we presented elective, sensitive, and rapid UV-Vis spectrophotometry and calorimetric assay for the recognition of digoxin. Therefore, cysteamine-gold nanoparticles (Cys A-AuNPs) in the presence of cysteine acid amine and Silver nanoparticles in the presence of tetramethyl benzidine and hydrogen peroxide (AgNPs-TMB [3,3′,5,5′-tetramethylbenzidine]-H₂O₂) were synthesized and utilized as the desired probe. Finally, color variation of probes was observed in the absence and presence of digoxin. Obtained results indicate that the color of Cys A-AuNPs changed from dark pink to light in the absence and the presence of digoxin, respectively. Also, the color of AgNPs-TMB-H₂O₂ changed from dark blue to light blue, in the absence and the presence of digoxin, respectively. Moreover, UV-Vis spectroscopies results indicate digoxin with a low limit of quantification of 0.125 ppm in human plasma samples which linear range was 0.125 to 11 ppm.

中文翻译：

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功能化AuNPs和三角形AgNPs作为高效光学纳米探针对地高辛的视觉监测和光学识别

在这项研究中，我们提出了选择性、灵敏和快速的紫外-可见分光光度法和量热法来识别地高辛。因此，半胱胺-金纳米粒子（Cys A-AuNPs）在半胱氨酸胺和银纳米粒子在四甲基联苯胺和过氧化氢的存在下（AgNPs-TMB [3,3',5,5'-四甲基联苯胺]-H ₂ O ₂ ) 被合成并用作所需的探针。最后，在不存在和存在地高辛的情况下观察到探针的颜色变化。获得的结果表明，在不存在和存在地高辛的情况下，Cys A-AuNPs 的颜色分别从深粉红色变为浅色。此外，AgNPs-TMB-H ₂ O _2的颜色分别在不存在和存在地高辛的情况下从深蓝色变为浅蓝色。此外，UV-Vis 光谱结果表明，地高辛在人血浆样品中的定量下限为 0.125 ppm，线性范围为 0.125 至 11 ppm。