Fakayode Sayo O, Bwambok David K, Banerjee Souvik, Rai Prateek, Okoth Ronald, Kuiters Corinne, Benjamin Ufuoma
Department of Chemistry and Physics, College of Arts and Sciences, University of North Carolina at Pembroke, 1 University Drive, Pembroke, NC 28372, USA.
Department of Chemistry, Ball State University, Muncie, IN 47306, USA.
Sensors (Basel). 2025 Sep 4;25(17):5505. doi: 10.3390/s25175505.
Nitrosamines, including N-nitroso diethylamine (NDEA) have emerged as pharmaceutical impurities and carcinogenic environmental contaminants of grave public health safety concerns. This study reports on the preparation and first use of cysteine-gold nanoparticles (CysAuNPs) for colorimetric detection of NDEA in human serum albumin (HSA) under physiological conditions. Molecular docking (MD) and molecular dynamic simulation (MDS) were performed to probe the interaction between NDEA and serum albumin. UV-visible absorption and fluorescence spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM) imaging were used to characterize the synthesized CysAuNPs. These CysAuNPs show a UV-visible absorbance wavelength maxima (λ) at 377 nm and emission λ at 623 nm. Results from DLS measurement revealed the CysAuNPs' uniform size distribution and high polydispersity index of 0.8. Microscopic imaging using TEM showed that CysAuNPs have spherical to nanoplate-like morphology. The addition of NDEA to HSA in the presence of CysAuNPs resulted in a remarkable increase in the absorbance of human serum albumin. The interaction of NDEA-CysAuNPs-HSA is plausibly facilitated by hydrogen bonding, sulfur linkages, or by Cys-NDEA-induced electrostatic and van der Waal interactions. These are due to the disruption of the disulfide bond linkage in Cys-Cys upon the addition of NDEA, causing the unfolding of the serum albumin and the dispersion of CysAuNPs. The combined use of molecular dynamic simulation and colorimetric experiment provided complementary data that allows robust analysis of NDEA in serum samples. In addition, the low cost of the UV-visible spectrophotometer and the easy preparation and optical sensitivity of CysAuNPs sensors are desirable, allowing the low detection limit of the CysAuNPs sensors, which are capable of detecting as little as 0.35 µM NDEA in serum albumin samples, making the protocol an attractive sensor for rapid detection of nitrosamines in biological samples.
亚硝胺，包括N-亚硝基二乙胺（NDEA），已成为严重影响公众健康安全的药物杂质和致癌环境污染物。本研究报告了半胱氨酸金纳米颗粒（CysAuNPs）的制备及其在生理条件下用于比色检测人血清白蛋白（HSA）中NDEA的首次应用。进行了分子对接（MD）和分子动力学模拟（MDS）以探究NDEA与血清白蛋白之间的相互作用。利用紫外可见吸收光谱、荧光光谱、动态光散射（DLS）和透射电子显微镜（TEM）成像对合成的CysAuNPs进行表征。这些CysAuNPs在377 nm处呈现紫外可见吸收波长最大值（λ），发射波长λ为623 nm。DLS测量结果显示CysAuNPs尺寸分布均匀，多分散指数高达0.8。TEM显微镜成像表明CysAuNPs具有球形到纳米片状的形态。在CysAuNPs存在下向HSA中添加NDEA会导致人血清白蛋白的吸光度显著增加。NDEA-CysAuNPs-HSA之间的相互作用可能是通过氢键、硫键，或由Cys-NDEA诱导的静电和范德华相互作用来促进的。这是由于添加NDEA后Cys-Cys中的二硫键断裂，导致血清白蛋白展开以及CysAuNPs分散。分子动力学模拟和比色实验的结合使用提供了互补数据，从而能够对血清样品中的NDEA进行可靠分析。此外，紫外可见分光光度计成本低，CysAuNPs传感器易于制备且具有光学敏感性，使得CysAuNPs传感器具有低检测限，能够检测血清白蛋白样品中低至0.35 μM的NDEA，这使得该方案成为用于快速检测生物样品中亚硝胺的有吸引力的传感器。
