基于CdSe/ZnS量子点的低毒水等效液体闪烁体的研制-《中国医学物理学杂志》

文章信息/Info

Title:: Development of a low-toxicity water-equivalent liquid scintillator based on CdSe/ZnS quantum dots

作者:: 褚薛刚1; 王君辉2; 张保国3; 邢晓汾1; 1.山西省肿瘤医院/中国医学科学院肿瘤医院山西医院/山西医科大学附属肿瘤医院放疗科，山西太原 030013； 2.南通市肿瘤医院放疗科，江苏南通 226361； 3.苏州大学放射医学与防护学院/省部共建“放射医学与辐射防护”国家重点实验室，江苏苏州 215123

Author(s):: CHU Xuegang1; WANG Junhui2; ZHANG Baoguo3; XING Xiaofen1; 1. Department of Radiotherapy, Cancer Hospital Affiliated to Shanxi Medical University/Shanxi Hospital Affiliated to Cancer Hospital, Chinese Academy of Medical Sciences/Shanxi Cancer Hospital, Taiyuan 030013, China 2. Department of Radiotherapy, Nantong Tumor Hospital, Nantong 226361, China 3. State Key Laboratory of Radiation Medicine and Radiation Protection/School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, China

Keywords:: Keywords: liquid scintillator quantum dot water-equivalent Geant4

摘要:: 目的：设计一种PPO为第一发光物质，油溶性的量子点作为第二发光物质，十二烷基苯为基质的新型低毒水等效液体闪烁体。方法：检测PPO的发射光谱、量子点（QD）的吸收光谱和发射光谱，并对不同浓度的QD作为第二发光物质的闪烁液进行辐射发光测试。首先用经验公式推算出组织等效液体闪烁体所需掺杂的量子点大致比例，然后用蒙卡模拟软件Geant4精确模拟出量子点的精确掺杂比例，并对其进行了水等效性和剂量学各项性能的测试。结果：PPO的发射波长峰值为366 nm，QD的激发波长峰值为340 nm，发射波长峰值为519 nm。当掺杂QD浓度为0.34 wt%时，水等效性最好。结论：量子点可以作为液体闪烁体的第二发光物质，可以通过蒙卡模拟来确定水等效时量子点的掺杂含量。

Abstract:: Abstract: Objective To develop a novel low-toxicity water-equivalent liquid scintillator with PPO as the primary luminescent substance, oil-soluble quantum dots (QD) as the secondary luminescent substance, and dodecylbenzene as the matrix. Methods The emission spectrum of PPO, as well as the absorption and emission spectra of QD were detected, and the radioluminescence tests were carried out on the scintillation liquids with different concentrations of QD as the secondary luminescent substance. After applying an empirical formula to deduce the approximate doping proportion of QD required for the tissue-equivalent liquid scintillator, the Monte Carlo simulation software Geant4 was used to accurately simulate the precise QD doping ratio, and finally, tests were conducted to evaluate the water equivalence and various dosimetric properties. Results The peak emission wavelength of PPO was 366 nm. For QD, the peak excitation wavelength was 340 nm, and the peak emission wavelength was 519 nm. Notably, the water equivalence was optimal when the QD doping concentration was 0.34 wt%. Conclusion QD can serve as the secondary luminescent substance for liquid scintillator, and the doping content of QD required to achieve water equivalent can be determined through Monte Carlo simulation.