A Novel Textile Wearable OECT-Integrated Smart Bandaid for Real-Time Uric Acid Monitoring in Wound Exudate

Wound care is a constantly expanding field, as in the medical world new solutions are required to treat chronic and/or severe wounds, which derive from pathologies or conditions such as diabetes, third-degree burns, or skin grafts. Today, a preventive type of approach is usually followed for treatment, using materials such as antibacterial fibers or nanoparticles- loaded hydrogels, along with the visual inspection of the wound site upon bandage removal, e.g., an operation which carries an intrinsic risk of infection and disturbance of the wound bed healing process. To address these issues, we developed a novel smart bandaid1 featuring a fully textile Organic Electrochemical Transistor (OECT) based on the conductive polymer poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) to monitor wound exudate uric acid levels (UA) in real-time, a crucial biomarker correlated with wound health status. The wearable devices were produced by screen-printing a PEDOT:PSS-based ink formulation on medical-grade gauzes, obtaining a smart medication with a passive sampling system, allowing for continuous, flow-conditions operativity. UA was quantified by means of potentiostatic determination, upon imposition of drain-source and gate-source voltage biases equal to -0.3 and +0.6 V, respectively. Different UA solution in Phosphate Buffer (PBS) or Synthetic Wound Exudate (SWE) were supplied using a HPLC pump at a flow-rate equal to 0.05 mL/min mimicking the natural emission of wound exudate. The devices reported a sensitivity equal to a 47% change in drain current for a 10-fold variation in UA concentration (R2 = 0.98) in both media, as statistically proven by performing a t-test (P = 0.95).