Diabetes Diagnosis with Dummies
A microfluidic pacifier has been designed to measure biomarkers in saliva – starting with glucose
Jonathan James | | Quick Read
Diagnosing rare genetic disorders early can make all the difference to newborns – and neonatal diabetes is no exception. However, invasive tests for glucose monitoring in neonates have obvious drawbacks and, because of the very rare nature of the disease, genetic tests are used for definitive diagnosis rather than for screening. Now, Alberto Escarpa of the University of Alcalá, Spain, along with colleagues at the University of California San Diego, USA, is pioneering a non-invasive approach: a pacifier – “dummy” in the UK – capable of monitoring glucose levels in saliva using a combination of microfluidics and electrochemical detection (1).
Saliva flows from the oral cavity into the exterior portion of the pacifier along a unidirectional flow channel before entering an electrochemical chamber. Here, glucose is converted into gluconic acid across a Prussian-Blue-GOx electrode, inducing a change in electrical potential, which is communicated to a computer or smartphone via wireless connection. “This is a truly non-invasive approach to measuring glucose levels in infant saliva,” says Escarpa. “And because our device so closely resembles a typical pacifier in terms of esthetics, we don’t anticipate rejection to be a major problem.”
So far, the device has only been tested on diabetic adults; moving studies into neonates will present additional analytical and safety-related challenges. “Reflux of milk is very common in infants and has the potential to interfere with the signal. Saliva pH is also susceptible to this phenomenon, bringing into question the validity of any readings,” says Escarpa, who must also further refine the design. “The device’s saliva channel is composed of several pieces – each of which could present a choke or swallow hazard should it become disconnected. In an ideal world the apparatus would be assembled as a single piece – this is the goal,” he says.
By integrating additional sensors, Escarpa believes he can increase the number of detectable biomarkers. “Conceivably, any saliva biomarker could be analyzed using this approach – including those indicative of infectious disease,” he says. “The possibilities are practically endless.”
- L García-Carmona et al., “Pacifier biosensor: toward noninvasive saliva biomarker monitoring”, Anal Chem, [Epub ahead of print] (2019). DOI: 10.1021/acs.analchem.9b03379