Advanced Wound Dressing for Real-Time pH Monitoring

Abstract

The rapid evolution of wearable technologies is giving rise to a strong push for textile chemical sensors design targeting the real-time collection of vital parameters for improved healthcare. Among the most promising applications, monitoring of nonhealing wounds is a scarcely explored medical field that still lacks quantitative tools for the management of the healing process. In this work, a smart bandage is developed for the real-time monitoring of wound pH, which has been reported to correlate with the healing stages, thus potentially giving direct access to the wound status without disturbing the wound bed. The fully textile device is realized by integrating a sensing layer, including the two-terminal pH sensor made of a semiconducting polymer and iridium oxide particles, and an absorbent layer ensuring the delivery of a continuous wound exudate flow across the sensor area. The two-terminal sensor exhibits a reversible response with a sensitivity of (59 ± 4) μA pH –1 in the medically relevant pH range for wound monitoring (pH 6–9), and its performance is not substantially affected either by the presence of the most common chemical interferents or by temperature gradients from 22 to 40 °C. Thanks to the robust sensing mechanism based on potentiometric transduction and the simple device geometry, the fully assembled smart bandage was successfully validated in flow analysis using synthetic wound exudate.

A Wearable Electrochemical Gas Sensor for Ammonia Detection

“…The Cr/Au (10/40 nm) tracks were thermally evaporated, as described elsewhere [ 28 , 30 ]. Then, CLEVIOS TM PH1000 suspension was mixed with EG, dodecylbenzene sulfonic acid and GOPS in the following volumetric ratio, 93.75:5:0.25:1, sonicated for 10 min and filtered using 1.2 μm cellulose acetate filters (Sartorius, Gottingen, Germany).…”

“…Afterwards, the devices were thermally annealed for 1 h at 140 °C to improve the film stability [ 31 ], and a mixture of PDMS-curing agent (9:1 w / w ) was applied over the Au contacts to ensure electrical insulation. The PEDOT:PSS film was electrochemically functionalised with iridium oxide particles (IrOx Ps), following a procedure described elsewhere [ 28 ]. Briefly, 10% wt.…”

“…Our group has recently developed a new approach inspired by the organic electrochemical transistor for the fabrication of sensors operating in an aqueous environment with a two-terminal structure typical of a chemiresistor [ 25 , 26 , 27 , 28 ]. The sensing strategy is based on the combination of a conductive polymer and a potentiometric responsive material, acting as the charge transport layer and the transducing element, respectively.…”

“…The result is the reversible modulation of the doping state of the conductive polymer, with the consequent variation of the current flowing across the film. This approach has recently been exploited for the design of a two-point probe, electrochemically gated sensors for Cl − and pH detection, operating in wound exudate [ 28 ] and sweat [ 25 , 27 ], focusing on healthcare applications.…”

Wireless Textile Moisture Sensor for Wound Care

“…Moreover, the high complexity of wound exudate and wide range of wound morphologies limits the application of the most common sensors [5,13]. Recent examples of smart bandage have been proposed for the detection of pH [14][15][16], uric acid and Bacteria infection [17,18].…”