Simultaneous electrochemical detection of glycated and human serum albumin for diabetes management

Abstract

Developing highly selective and sensitive biosensors for diabetes management blood glucose monitoring is essential to reduce the health risks associated with diabetes. Assessing the glycation (GA) of human serum albumin (HSA) serves as an indicator for medium-term glycemic control, making it suitable for assessing the efficacy of blood glucose management protocols. However, most biosensors are not capable of simultaneous detection of the relative fraction of GA to HSA in a clinically relevant range. Here, we report an effective miniaturised biosensor architecture for simultaneous electrochemical detection of HSA and GA across relevant concentration ranges. We immobilise DNA aptamers specific for the detection of HSA and GA on gold nanoislands (Au NIs) decorated screen-printed carbon electrodes (SPCEs), and effectively passivate the residual surface sites. We achieve a dynamic detection range between 20 and 60 mg/mL for HSA and 1–40 mg/mL for GA in buffer solutions. The analytical utility of our HSA and GA biosensor architectures are validated in mice serum indicating immediate potential for clinical applications. Since HSA and GA have similar structures, we extensively assess our sensor specificity, observing high selectivity of the HSA and GA sensors against each other and other commonly present interfering molecules in blood such as glucose, glycine, ampicillin, and insulin. Additionally, we determine the glycation ratio, which is a crucial metric for assessing blood glucose management efficacy, in an extensive range representing healthy and poor blood glucose management profiles. These findings provide strong evidence for the clinical potential of our biosensor architecture for point-of-care and self-assessment of diabetes management protocols.