Department of Applied Physics, Graduate School of Engineering, Osaka University , 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan.
Department of Pharmacology and Toxicology, Faculty of Arts and Sciences, University of Toronto , 27 King's College Circle, Toronto, Ontario M5S 1A1, Canada.
Anal Chem. 2017 Jun 6;89(11):5909-5915. doi: 10.1021/acs.analchem.7b00280. Epub 2017 May 16.
Monitoring of blood glucose content is vital for diabetes patients. The conventional widely used method involves an invasive procedure for blood sampling. In addition, blood glucose measured by this way is affected by immediate food consumption and it does not show accurate baseline blood glucose measurement. Thus, monitoring blood glucose by a noninvasive method that accurately reflects baseline blood glucose content is important. Glycated albumin (GA), a biomarker for diabetes indicating the average blood glucose over 2 weeks, can be used for semilong-term blood glucose monitoring. Detection of GA in saliva is a noninvasive method that alleviates the use of needles for diabetic patients; however, its content in saliva is in the nanomolar range. Therefore, the GA enzymatic detection method was combined with the ECL method for a highly sensitive detection of GA in human serum albumin and in the saliva sample. Here, the standard curve was constructed using model substrate, FZK, between 0.1 and 2 μM, and GA in human serum albumin was measured in this range. Also, we successfully demonstrated the detection limit of 0.1 μM GA in human serum albumin sample using ECL, which has seen improvement of about 70 times more than the colorimetric methods. The detection of GA in real saliva sample suggested that sample dilution of 5 times may be necessary to suppress the ECL quenching effect by impurities.
血糖监测对糖尿病患者至关重要。传统的广泛使用的方法涉及到血液采样的侵入性程序。此外，通过这种方式测量的血糖受到即时食物消耗的影响，并且不能显示准确的基础血糖测量值。因此，通过准确反映基础血糖含量的非侵入性方法监测血糖非常重要。糖化白蛋白（GA）是一种糖尿病生物标志物，可指示 2 周内的平均血糖水平，可用于半长期血糖监测。检测唾液中的 GA 是一种非侵入性方法，可以减轻糖尿病患者使用针头的痛苦；然而，其在唾液中的含量处于纳摩尔范围。因此，将 GA 酶检测方法与 ECL 方法结合起来，用于人血清白蛋白和唾液样本中 GA 的高灵敏度检测。在这里，使用标准底物 FZK 在 0.1 到 2 μM 之间构建了标准曲线，并在该范围内测量了人血清白蛋白中的 GA。此外，我们成功地利用 ECL 检测到 0.1 μM GA 在人血清白蛋白样本中的检测限，比比色法提高了约 70 倍。在真实唾液样本中检测 GA 表明，可能需要将样品稀释 5 倍，以抑制杂质对 ECL 猝灭效应的影响。
