Fully Textile Biosensing Platforms for Real Time Monitoring of Biofluids

The development of wearable sensors, in particular fully-textile ones, is one of the most interesting open challenges in bioelectronics.<br/>Here we present two examples of fully textile biosensing platforms based on the conducting polymer poly(3,4-thylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS), for healthcare and sport activities real-time monitoring.<br/>The first application consists of simple threads, based on natural and synthetic fibers, coated by PEDOT:PSS and properly functionalized with either a nano-composite material or a chemical sensitive dye to obtain Cl− and pH selective sensing functionality, respectively. The single-thread sensors show excellent sensitivity, reproducibility, selectivity, long term stability and no cross interference and they can be knitted or sewed into fabrics, opening up a new vision for a textile wearable multi-sensing platform achievable in the near future[1].<br/>The second application consists in the integration of textile sensors in a medical bandage, to directly obtain real time information on moisture status, uric acid concentration and pH level of wound exudate.<br/>Monitoring the healing stages of hard-to-heal wounds is challenging since it can allow for better-targeted therapies and faster patient recovery, without removing the bandage and disturbing the wound bed.<br/>The three proposed sensors are obtained by screen printing PEDOT:PSS on a medical gauze and, for all the proposed devices a key feature is the use of special medical-grade textile materials that provide a passive sampling system, thus enabling the continuous, real-time and non-invasive analysis of wound fluid.<br/>The moisture sensor, directly integrated with an RFID chip implementing a real-time wireless monitoring, operates by detecting impedance variations that span over several orders of magnitude between dry and wet states. [2].<br/>The pH sensor 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. It exhibits a reversible response with a sensitivity of (59 ± 4) μA pH-1 in the medically relevant pH range for wound monitoring [3].<br/>The sensor for UA is an all PEDOT:PSS OECT that can reliably and reversibly detect UA concentration in synthetic wound exudate in the biologically relevant range of 220−750 μM. Its behaviour is tested in flow conditions for better mimicking the real wound bed [4].<br/>REFERENCES<br/>[1] L. Possanzini, F. Decataldo, F. Mariani, I. Gualandi, M. Tessarolo, E. Scavetta, B. Fraboni, Scientific Reports <b>2020</b>, <i>10</i>, 17180.<br/>[2] M. Tessarolo, L. Possanzini, I. Gualandi, F. Mariani, L. Torchia, D. Arcangeli, F. Melandri, E. Scavetta, B. Fraboni <i>Frontiers in Physics</i> <b>2021</b>, 9, 722173<br/>[3] F. Mariani, M. Serafini, I. Gualandi, D. Arcangeli, F. Decataldo, L. Possanzini, M. Tessarolo, D. Tonelli, B. Fraboni, E. Scavetta <i>ACS Sensors</i> 6 <b>2021</b>, 2366−2377<br/>[4] D. Arcangeli, I. Gualandi, F. Mariani, M. Tessarolo, F. Ceccardi, F. Decataldo, F. Melandri, D. Tonelli, B. Fraboni, E. Scavetta <i>ACS Sensors </i><b>2023</b>, 8, 1593−1608