Sensitive Detection of Glycated Albumin in Human Serum Albumin Using Electrochemiluminescence

• Published in: Analytical chemistry (Washington) Vol. 89; no. 11; pp. 5909 - 5915
• Main Authors: Inoue, Yuki, Inoue, Mikako, Saito, Masato, Yoshikawa, Hiroyuki, Tamiya, Eiichi
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 06.06.2017
• Subjects: Albumin; Biomarkers; Blood; Blood glucose; blood sampling; Blood tests; Chemistry; Colorimetry; detection limit; Diabetes; Diabetes mellitus; Dilution; Electrochemiluminescence; Electroluminescence; Food consumption; Glucose; Glucose monitoring; Human serum albumin; Hypodermic needles; Impurities; Monitoring; Needles; Patients; Proteins; Quenching; Saliva; Serum albumin
• ISSN: 0003-2700; 1520-6882; 1520-6882
• DOI: 10.1021/acs.analchem.7b00280

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.