Sakonsinsiri Chadamas, Puangmali Theerapong, Sreejivungsa Kaniknun, Koowattanasuchat Sireemas, Thanan Raynoo, Chompoosor Apiwat, Kulchat Sirinan, Sithithaworn Paiboon
Department of Biochemistry, Faculty of Medicine, Khon Kaen University Khon Kaen 40002 Thailand
Cholangiocarcinoma Research Institute, Khon Kaen University Khon Kaen 40002 Thailand.
RSC Adv. 2022 Sep 7;12(39):25478-25486. doi: 10.1039/d2ra01858f. eCollection 2022 Sep 5.
8-Oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) is a crucial biomarker for oxidative DNA damage and carcinogenesis. Current strategies for 8-oxo-dG detection often require sophisticated instruments and qualified personnel. In this study, cysteamine-stabilised gold nanoparticles (cyst-AuNPs) were synthesised and used for colorimetric detection of 8-oxo-dG in urine. Sensing of 8-oxo-dG is based on the anti-aggregation of cyst-AuNPs, mediated by the specific recognition of 8-oxo-dG and its aptamer. In the absence of 8-oxo-dG, the aptamer was adsorbed onto the surface of cyst-AuNPs, resulting in aggregation and the development of a purple colour solution. Upon addition of the target molecule 8-oxo-dG, the aptamer specifically bound to it and could not induce the aggregation of cyst-AuNPs, leading to the dispersion of cyst-AuNPs in the solution. Simple visual examination could be used to monitor the purple-to-red colour change that started at 12 nM, a threshold concentration for visual analysis. The absorbance at 525 nm increased in direct relation to the number of the target molecule 8-oxo-dG. This aptamer/cyst-AuNPs system showed excellent sensing ability for the 8-oxo-dG concentration in the range of 15-100 nM, with a detection limit as low as 10.3 nM and a detection time of 30 min. Interference experiments showed that the developed colorimetric strategy had a good sensitivity. This simple and rapid colorimetric method has successfully been applied to inspect 8-oxo-dG concentration in real urine samples and provided recoveries between 93.6 and 94.1%, with a limit of quantification (LOQ) of 34.3 nM, which was comparable with an enzyme-linked immunosorbent-based detection of 8-oxo-dG. This new, easy-to-use, and rapid method could be used as an alternative and initiative strategy for the development of an on-site analysis of 8-oxo-dG in urine.
8-氧代-7,8-二氢-2'-脱氧鸟苷（8-氧代-dG）是氧化DNA损伤和致癌作用的关键生物标志物。当前检测8-氧代-dG的策略通常需要精密仪器和专业人员。在本研究中，合成了半胱胺稳定的金纳米颗粒（cyst-AuNPs）并用于尿液中8-氧代-dG的比色检测。8-氧代-dG的传感基于cyst-AuNPs的抗聚集作用，由8-氧代-dG及其适配体的特异性识别介导。在没有8-氧代-dG的情况下，适配体吸附在cyst-AuNPs表面，导致聚集并形成紫色溶液。加入目标分子8-氧代-dG后，适配体与之特异性结合，无法诱导cyst-AuNPs聚集，导致cyst-AuNPs在溶液中分散。简单的目视检查可用于监测从12 nM开始的紫到红的颜色变化，这是目视分析的阈值浓度。525 nm处的吸光度与目标分子8-氧代-dG的数量直接相关。该适配体/cyst-AuNPs系统对15 - 100 nM范围内的8-氧代-dG浓度显示出优异的传感能力，检测限低至10.3 nM，检测时间为30分钟。干扰实验表明，所开发的比色策略具有良好的灵敏度。这种简单快速的比色方法已成功应用于检测实际尿液样本中的8-氧代-dG浓度，回收率在93.6%至94.1%之间，定量限（LOQ）为34.3 nM，与基于酶联免疫吸附的8-氧代-dG检测相当。这种新型、易于使用且快速的方法可作为尿液中8-氧代-dG现场分析开发的替代和首创策略。
