Sriondee Y.Vijitvarasan P.Rattanachata A.Nakajima H.Oaew S.Cheunkar S.Mahidol University2024-02-082024-02-082023-01-01Analytical Methods (2023)17599660https://repository.li.mahidol.ac.th/handle/20.500.14594/95753Glycated hemoglobin (HbA1c) has been an important biomarker for long-term diagnosis and monitoring of diabetes mellitus. The development of a rapid, reliable, and less sophisticated device to measure HbA1c is imperative to facilitate efficient early-care diabetes management. To date, no existing aptamer-based biosensor (aptasensor) for detecting HbA1c has been developed using a quartz crystal microbalance (QCM). In this study, the aptamer specific to HbA1c as a novel biosensing receptor was covalently functionalized onto a QCM substrate via mixed self-assembled monolayers (SAMs). A portable QCM equipped with a liquid-flow module was used to investigate the biospecificity, sensitivity, and interaction dynamics of the aptamer functionalized surfaces. The real-time kinetic analysis of HbA1c binding to the surface-functionalized aptamers revealed “on” and “off” binding rates of 4.19 × 104 M−1 s−1 and 2.43 × 10−3 s−1, respectively. These kinetic parameters imply that the QCM-based aptasensor specifically recognizes HbA1c with an equilibrium dissociation constant as low as 57.99 nM. The linear detection of HbA1c spanned from 13 to 108 nM, with a limit of detection (LOD) of 26.29 nM. Moreover, the spiked plasma sample analysis offered compelling evidence that this aptasensor is a promising technique for developing a point-of-care device for diabetes mellitus.Chemical EngineeringChemistryEngineeringArticleSCOPUS10.1039/d3ay01842c2-s2.0-851823709891759967938197200