Abstract Studies involving nanoparticle uptake in cells and tissues are contingent upon adequate methods of quantification. For gold nanoparticles (AuNPs), the quantification of uptake typically relies on inductively coupled plasma (ICP) based techniques which require sample pre-treatment and large sample volume (5–10 ml). To address these shortcomings, a total reflection X-Ray fluorescence (TXRF) spectroscopy-based method was developed to measure uptake of AuNPs in breast (MDA-MB-231) and prostate (PC3) cancer cells without any sample pre-treatment. In order to directly compare the quantification of TXRF and ICP Atomic Emission Spectroscopy (ICP-AES), samples were pre-treated with the most commonly used ICP-AES wet digestion protocol adopted from literature. The accuracy of both spectrometers was assessed by calculating the recovery rate of 10 nm reference material AuNPs in MDA-MB-231 and PC3 cells. TXRF showed analytically acceptable recovery rates of 96.1% and 98.7% for unfiltered MDA-MB-231 and PC3 cells, respectively, while ICP-AES showed low recovery rate of 23.3% and 27.8% for filtered samples. The nearly 80% underestimation by ICP-AES highlights the importance of proper sample pre-treatment for ICP-based measurements. Furthermore, it also has important implications in the clinical translation of AuNPs as knowledge of uptake is required for determining the nanoparticle injected dose. This work demonstrates TXRF's ability to accurately quantify AuNP without ICP-required wet digestion protocols using only 5 μl of sample per reflector, making the technique a suitable alternative to ICP-AES.

中文翻译：

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比较全反射 X 射线荧光光谱和电感耦合等离子体对金纳米颗粒吸收的量化

摘要 涉及细胞和组织中纳米颗粒摄取的研究取决于适当的量化方法。对于金纳米粒子 (AuNP)，摄取的量化通常依赖于基于电感耦合等离子体 (ICP) 的技术，该技术需要样品预处理和大样品体积 (5–10 ml)。为了解决这些缺点，开发了一种基于全反射 X 射线荧光 (TXRF) 光谱的方法来测量乳腺癌 (MDA-MB-231) 和前列腺 (PC3) 癌细胞中 AuNP 的吸收，而无需任何样品预处理。为了直接比较 TXRF 和 ICP 原子发射光谱 (ICP-AES) 的定量，使用文献中最常用的 ICP-AES 湿消解方案对样品进行预处理。通过计算 MDA-MB-231 和 PC3 细胞中 10 nm 参考材料 AuNP 的回收率来评估两种光谱仪的准确性。TXRF 对未过滤的 MDA-MB-231 和 PC3 细胞显示出分析可接受的回收率分别为 96.1% 和 98.7%，而 ICP-AES 对过滤后的样品显示出低回收率，分别为 23.3% 和 27.8%。ICP-AES 近 80% 的低估突出了适当的样品预处理对于基于 ICP 的测量的重要性。此外，它还对 AuNP 的临床转化具有重要意义，因为确定纳米颗粒注射剂量需要吸收知识。这项工作证明了 TXRF 能够准确量化 AuNP，而无需 ICP 要求的湿消解协议，每个反射器仅使用 5 μl 样品，使该技术成为 ICP-AES 的合适替代品。