Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan.
Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu, Taiwan.
J Nanobiotechnology. 2024 Sep 28;22(1):585. doi: 10.1186/s12951-024-02850-5.
Redox imbalance and oxidative stress are increasingly recognized as significant factors in health disorders such as neurodegenerative disorders, premature aging and cancer. However, detecting antioxidant levels that is crucial for managing oxidative stress, can be challenging due to existing assays' limitations, such as insensitivity to thiol-containing antioxidants. This study presents a simple fluorescence-based assay for antioxidant detection employing the enhanced photocatalytic oxidase-like activity of dithiothreitol (DTT)-assisted bovine serum albumin (BSA)-stabilized gold nanoclusters (DTT@BSA-AuNCs). The reported nanozyme exhibits remarkable stability, versatility, and catalytic activity. Under LED irradiation, DTT@BSA-AuNCs generate singlet oxygen, which converts non-fluorescent thiamine to fluorescent thiochrome, utilizing dissolved oxygen for catalysis. Antioxidants inhibit thiochrome formation, leading to fluorescence quenching. This method enables sensitive detection of antioxidants such as ascorbic acid and glutathione with limits of detection of 0.08 µM and 0.32 µM, respectively, under neutral pH, outperforming previous studies. The assay successfully detects antioxidants in human saliva and cancer cell models. The DTT@BSA-AuNCs-based assay offers a cost-effective, sensitive, and straightforward approach for detecting antioxidants in biological samples, facilitating improved monitoring of oxidative stress in various diseases.
氧化还原失衡和氧化应激被越来越多地认为是神经退行性疾病、早衰和癌症等健康障碍的重要因素。然而，由于现有检测方法的局限性，如对含巯基抗氧化剂的不敏感，检测对抗氧化应激至关重要的抗氧化剂水平具有挑战性。本研究提出了一种简单的荧光法，用于检测抗氧化剂，该方法利用二硫苏糖醇（DTT）辅助牛血清白蛋白（BSA）稳定的金纳米簇（DTT@BSA-AuNCs）的增强类过氧化物酶氧化酶活性。所报道的纳米酶具有显著的稳定性、多功能性和催化活性。在 LED 照射下，DTT@BSA-AuNCs 产生单线态氧，利用溶解氧进行催化，将非荧光硫胺素转化为荧光硫代色酮。抗氧化剂抑制硫代色酮的形成，导致荧光猝灭。该方法能够在中性 pH 条件下，以 0.08 μM 和 0.32 μM 的检测限，灵敏地检测抗坏血酸和谷胱甘肽等抗氧化剂，优于以前的研究。该测定法成功地检测了人唾液和癌细胞模型中的抗氧化剂。基于 DTT@BSA-AuNCs 的测定法为检测生物样品中的抗氧化剂提供了一种经济有效、灵敏和简单的方法，有助于改善各种疾病中氧化应激的监测。
