Abstract Gold nanoparticles (AuNPs) are being investigated extensively for their role as radiosensitisers. Studies have shown that they are effective dose enhancing agents. One of the main factors that enables AuNPs to function as dose enhancing agents is their ability to generate reactive oxygen species under X-ray irradiation. In this study, we investigated this issue utilising a chemiluminescence technique with 3’-(p-aminophenyl) fluorescein (APF) in a phantom. First, we examined the time variation and dose response of the fluorescence intensity of APF for spherical 50 nm AuNPs exposed to a 6 MV photon beam. The APF reagent was added to the AuNPs suspension in a small tube fixed in a water phantom. The fluorescence intensities of APF were measured using a microplate reader. Next, based on the APF response, we evaluated the dose enhancements caused by AuNPs in a 6 MV flattening filter (FF) and flattening filter-free (FFF) photon beams and doses of either 2, 4, or 6 Gy. While the time variation of APF fluorescence intensity without AuNPs was less than 5% after X-ray irradiation, we observed an increase in the fluorescence intensity over time in the presence of AuNPs without the radiation. The APF signals had a linear response to X-ray irradiation in a dose-dependent manner. The measured dose enhancement ratios for the FFF beam were significantly higher than that for the FF beam in the presence of 30 μg/ml AuNPs. This result shows APF can successfully detect differences in dose enhancement between the FF and FFF beams using AuNPs. In conclusion, the chemiluminescence technique using APF is a useful and simple method to estimate the level of dose enhancement caused by nanoparticles in a phantom.

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利用化学发光方法测量金纳米粒子引起的辐射剂量增强：基于幻像的研究

摘要 金纳米粒子 (AuNPs) 因其作为放射增敏剂的作用而受到广泛研究。研究表明它们是有效的剂量增强剂。使 AuNPs 作为剂量增强剂发挥作用的主要因素之一是它们在 X 射线照射下产生活性氧的能力。在这项研究中，我们利用幻影中的 3'-（对氨基苯基）荧光素 (APF) 的化学发光技术研究了这个问题。首先，我们检查了暴露于 6 MV 光子束的球形 50 nm AuNP 的 APF 荧光强度的时间变化和剂量响应。将 APF 试剂添加到固定在水模型中的小管中的 AuNPs 悬浮液中。使用酶标仪测量 APF 的荧光强度。接下来，根据 APF 响应，我们评估了由 6 MV 平坦滤波器 (FF) 和平坦无过滤器 (FFF) 光子束和 2、4 或 6 Gy 剂量中的 AuNP 引起的剂量增强。虽然在 X 射线照射后没有 AuNPs 的 APF 荧光强度的时间变化小于 5%，但我们观察到在没有辐射的 AuNPs 存在下荧光强度随时间增加。APF 信号对 X 射线照射呈剂量依赖性线性响应。在存在 30 μg/ml AuNP 的情况下，FFF 光束的测量剂量增强比显着高于 FF 光束。该结果表明 APF 可以使用 AuNP 成功检测 FF 和 FFF 光束之间剂量增强的差异。综上所述，