Development of Wearable Microneedle-Based Platform for Real-Time Biomarkers Sensing

The wearable device technology plays a huge role in the healthcare sector owing to the aging global population and increased acquisition of the internet of things (IoT). Further, the Coronavirus Disease-2019 (COVID-19) pandemic has accelerated the emergence of wearable medical devices in the market. The patients with chronic diseases are more focused on tracking single or multiple nutrients and biomarkers in the body. Diabetes is a classic example of chronic disease where the patients need to monitor their blood glucose level for a long time. In addition, diabetic patients also face electrolyte imbalance which gives rise to several other diseases. There is an immense urgency to develop a sensing platform that can detect the essential ions as well as biomarkers from the interstitial fluid (ISF) as it contains valuable information about the physiological status of a person. According to Centers for Disease Control and Prevention (CDC), imbalance of sodium concentration in the body may lead to stroke, hypertension, and epilepsy; for potassium: arrhythmia, chronic kidney disease (CKD), and dizziness; for calcium: depression, osteoporosis, and other bone-related disease; for pH of body fluid: urinary tract infection, respiratory acidosis, and sleep apnea. Within this advent of wearables, microneedle (MN)-based transdermal sensors are well positioned to play a key role in combining the significant benefits of dermal interstitial fluid (ISF) as a source of clinical indicators and minimally invasive skin puncturing to allow the collection of real-time diagnostic data. In this context, we have developed a MNs based versatile platform for the transdermal amperometric detection of glucose and different clinically relevant biomarkers such as K + , Na + , Ca 2+ in the body fluid in a robust, reliable, and cost-effective way. Here, stainless steel microneedle (SS-MN) is used as an ideal candidate for multiplex sensing due to its great chemical stability as well as the rigidity for accurate and painless puncture. The device is fabricated with ion selective electrode (ISM) coating on each needle for their corresponding electrolyte and enzyme for glucose detection. In vitro experiments performed in artificial ISF samples yielded excellent sensitivity and a good linear response. The sensor is successfully applied for in vivo detection of glucose and these ions in SD rats for validating their feasibility as a real-time sensing device. Overall, this developed concept comprises of significant progress in the sensing of glucose and other ions in relation to an electrolyte imbalance in the humans that holds relevance in controlling several diseases.