Faculty of Dentistry, Université Laval, 2420 Rue de la Terrasse, Quebec City, G1V0A6, Canada; Laboratory of Precision Oral Health and Chronobiology, College of Dentistry, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, S7N 5E4, Canada; Division of Biomedical Engineering, University of Saskatchewan, 57 Campus Dr, Saskatoon, S7K 5A9, Canada; Laboratory of Oral, Head and Neck Cancer - Personalized Diagnostics and Therapeutics, Department of Surgery, College of Medicine, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, S7N 5E4, Canada.
Laboratory of Precision Oral Health and Chronobiology, College of Dentistry, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, S7N 5E4, Canada.
Anal Chim Acta. 2023 Oct 23;1279:341777. doi: 10.1016/j.aca.2023.341777. Epub 2023 Sep 2.
Salivary melatonin is a clinically used biomarker for diagnosing circadian rhythm sleep disorders. Current melatonin detection assays are complex, expensive, and in many cases do not adequately measure low levels of salivary melatonin. Precisely measuring melatonin levels at multiple time points is crucial for determining dim light melatonin onset to evaluate its circadian fluctuation as well as the extent of circadian disruption and consequently adapt treatment regimens. Moreover, melatonin low levels in saliva challenges the reliability of routine clinical testing. This paper presents the development of a novel, highly sensitive, yet cost-effective, colorimetric assay for the rapid detection of salivary melatonin utilizing aptamer-AuNPs. Among several types of the aptamer tested, the 36-mer MLT-A-2 aptamer-AuNP probe showed the highest sensitivity with a melatonin limit of detection of 0.0011 nM along with a limit of quantification of 0.0021 nM in saliva. Moreover, our assay showed preferential interaction with melatonin when tested in presence of other structurally similar counter-targets. Taken together, this study provides new parameters for a melatonin assay that meets adequate levels of sensitivity and selectivity. The developed colorimetric assay could be adapted in a point-of-care system for profiling salivary melatonin levels at multiple time points during 24 h, crucial for accurately diagnosing and monitoring circadian rhythm sleep disorders and beyond.
唾液褪黑素是一种用于诊断昼夜节律睡眠障碍的临床生物标志物。目前的褪黑素检测方法复杂、昂贵，在许多情况下无法充分测量低水平的唾液褪黑素。精确测量多个时间点的褪黑素水平对于确定弱光褪黑素起始时间以评估其昼夜波动以及昼夜节律紊乱的程度从而调整治疗方案至关重要。此外，唾液中褪黑素水平低挑战了常规临床检测的可靠性。本文介绍了一种利用适体-AuNPs 快速检测唾液褪黑素的新型、高灵敏度但具有成本效益的比色测定法的开发。在测试的几种适体中，36 -mer MLT-A-2 适体-AuNP 探针表现出最高的灵敏度，在唾液中的检测限为 0.0011 nM，定量限为 0.0021 nM。此外，当在存在其他结构相似的对照靶子时，我们的测定法显示出与褪黑素的优先相互作用。总之，这项研究为褪黑素测定法提供了新的参数，该方法具有足够的灵敏度和选择性。开发的比色测定法可以适应即时护理系统，在 24 小时内多个时间点对唾液褪黑素水平进行分析，这对于准确诊断和监测昼夜节律睡眠障碍及其他疾病至关重要。
