Groundbreaking Saliva-Derived Glucose Detector Set to Transform Diabetes Management
Researchers from King Abdullah University of Science & Technology (KAUST) have engineered a sensor capable of assessing glucose concentrations in saliva. This development offers an alternative pathway for diabetic individuals to manage their blood glucose levels.
A Novel Approach to Simplifying Diabetes Surveillance
The experimental sensor designed to gauge glucose levels in saliva could provide a straightforward, quick, and non-invasive method for diabetes self-monitoring, say the KAUST researchers responsible for this breakthrough technology.
Diabetes manifests when the body fails to properly control blood sugar levels. Elevated levels of glucose can result in cardiovascular diseases among other medical complications, making it crucial for diabetic individuals to keep their blood glucose within reasonable bounds.
Historically, individuals with diabetes have resorted to devices that require drawing a blood sample via a finger prick multiple times a day to monitor glucose levels. More recently, subcutaneous sensors have been deployed for continuous glucose measurement, eliminating the need for frequent finger pricks. However, these implanted sensors may be less precise at lower glucose concentrations and are not yet authorized for pediatric use.
Saliva: A Viable Substitute for Blood-Based Testing
Testing glucose levels via saliva is a more practical approach as it is linked to blood glucose concentrations. Nevertheless, glucose levels in saliva are markedly lower than in blood, complicating accurate measurements without the aid of advanced laboratory equipment.
The researchers at KAUST have developed an ultra-sensitive glucose monitoring system using thin-film transistors. These compact, low-energy devices hold potential for large-scale manufacturing as cost-effective, disposable sensors, according to team member Abhinav Sharma. “A user-friendly, non-invasive device that employs saliva as the test medium could fundamentally alter the lives of millions of patients globally,” he states.
Operational Mechanism of the Device
The transistor is comprised of fine layers of semiconductor materials such as indium oxide and zinc oxide, coated with the enzyme glucose oxidase. When saliva is applied to the sensor, this enzyme oxidizes any glucose, resulting in the formation of D-gluconolactone and hydrogen peroxide. The electrical oxidation of hydrogen peroxide subsequently generates electrons that penetrate the semiconductor layers, modifying the current within the semiconductors. The magnitude of this change reveals the glucose concentration in the sample.
Experiments on the device used human saliva samples with varying glucose levels, as well as samples from volunteers who had abstained from eating prior to the test. The sensor accurately identified a broad spectrum of glucose concentrations in less than a minute and was not compromised by other saliva components like fructose or sucrose. Although its sensitivity diminished over time, the device still performed well after two weeks of storage at ambient temperature.
Prospective Developments
The research team is currently working on creating an array of transistor sensors capable of detecting multiple metabolites in saliva concurrently. “The progression towards portable sensor arrays that can interface with smartphones is a prospective avenue for future research,” notes Thomas Anthopoulos, who spearheaded the research team.
Reference: “Non-invasive, ultrasensitive detection of glucose in saliva using metal oxide transistors” by Abhinav Sharma, et al., published on 15 June 2023 in Biosensors and Bioelectronics.
DOI: 10.1016/j.bios.2023.115448
