A Fully‑Printed Wearable Bandage‑Based Electrochemical Sensor with pH Correction for Wound Infection Monitoring

Wearable sensing systems have been designed to monitor health conditions in real-time by detecting analytes in human biofluids.Wound diagnosis remains challenging,necessitating suitable materials for high-performance wearable sensors to offer prompt feedback.Existing devices have limitations in measuring pH and the concentration of pH-dependent electroactive species simultaneously,which is crucial for obtaining a comprehensive understanding of wound status and optimizing biosensors.Therefore,improving materials and analysis system accuracy is essential.This article introduces the first example of a flexible array capable of detecting pyocyanin,a bacterial virulence factor,while correcting dynamic pH fluctuations.We demonstrate that this combined sensor enhances accuracy by mitigating the impact of pH variability on pyocyanin sensor response.Customized screen-printable inks were developed to enhance analytical performance.The analytical performances of two sensitive sensor systems(i.e.,fully-printed porous graphene/multiwalled carbon nanotube(CNT)and polyaniline/CNT composites for pyocyanin and pH sensors)are evaluated.Partial least square regression is employed to analyze nonzero-order data arrays from square wave voltammetric and potentiometric measurements of pyocyanin and pH sensors to establish a predictive model for pyocyanin concentration in complex fluids.This sensitive and effective strategy shows potential for personalized applications due to its affordability,ease of use,and ability to adjust for dynamic pH changes.

Conductive Biomaterials as Bioactive Wound Dressing for Wound Healing and Skin Tissue Engineering

Conductive biomaterials based on conductive polymers,carbon nanomaterials,or conductive inorganic nanomaterials demonstrate great potential in wound healing and skin tissue engineering,owing to the similar conductivity to human skin,good antioxidant and antibacterial activities,electrically controlled drug delivery,and photothermal effect.However,a review highlights the design and application of conductive biomaterials for wound healing and skin tissue engineering is lacking.In this review,the design and fabrication methods of conductive biomaterials with various structural forms including film,nanofiber,membrane,hydrogel,sponge,foam,and acellular dermal matrix for applications in wound healing and skin tissue engineering and the corresponding mechanism in promoting the healing process were summarized.The approaches that conductive biomaterials realize their great value in healing wounds via three main strategies(electrotherapy,wound dressing,and wound assessment)were reviewed.The application of conductive biomaterials as wound dressing when facing different wounds including acute wound and chronic wound(infected wound and diabetic wound)and for wound monitoring is discussed in detail.The challenges and perspectives in designing and developing multifunctional conductive biomaterials are proposed as well.

A reduced graphene oxide-coated conductive surgical silk suture targeting microresistance sensing changes for wound healing

Conventional sutures used in surgical procedures often lack the capability to effectively monitor physical and chemical activities or the microbial environment of surgical wounds due to their inadequate mechanical properties,insufficient electrical accuracy and unstability.Here,we present a straightforward layer-by-layer coating technique that utilizes 3-glycidoxypropyltrimethoxysilane(CA),graphene oxide(GO),and ascorbic acid(AA)to develop conductive silk-based surgical sutures(CA-rGSFS).The CA-rGSFS feature a continuous reduced graphene oxide(rGO)film on their surface,forming robust hydrogen bonds with silk fibroin.The reduction process of rGO is confirmed through Raman analysis,demonstrating an enhanced D peak to G peak ratio.Notably,the CA-rGSFS exhibit exceptional mechanical properties and efficient electron transmission,with a knot-pull tensile strength of 2089.72±1.20 cN and an electrical conductivity of 130.30±11.34 S/m,respectively,meeting the requirements specified by the United States Pharmacopeia(USP)for 2-0 sutures.These novel CA-rGSFS demonstrate the ability to accurately track resistance changes in various fluid environments with rapid response,including saline,intestinal,and gastric fluids.The suture also retains remarkable stretchablility and stability even after enduring 3000 tensile cycles,highlighting their potential for precise surgical site monitoring during the wound healing process.

Wet Spinning Fabrication of Robust and Uniform Intrinsically Conductive Cellulose Nanofibril/Silk Conductive Fibers as Bifunctional Strain/Humidity Sensor in Potential Smart Dressing

Silk fibroin(SF)with skin-like features and function shows great prospects in wearable electronics and smart dressing.However,the traditional method of loading conductive materials on physical interfaces can easily lead to the detachment of conductive materials,poor mechanical properties,and unstable conductivity,which hinder their practical application.Herein,simple wet spinning was utilized to fabricate multifunctional regenerated silk fibers reinforced with different contents of intrinsically conductive cellulose nanofibril(CNFene).Significant enhancements in fiber homogeneity,thermal stability,conductivity,mechanical strength,and sensing ability were achieved due to more regular orientation of silk fibroin molecules and strong intermolecular interactions with CNFene.The optimized sample(SF_(1))with high sensitivity(100 ms),excellent washing/rubbing resistance,and superb waterproof properties(22 days)can comprehensively monitor human motion and weak signals.Surprisingly,inspired by the different humidity levels around wounds at different stages of healing,SF1 with favorable humidity sensitivity can be developed as a smart dressing for monitoring wound healing.Therefore,this work provides a simple preparation route of smart high-performance fiber for flexible electronic devices,smart dressing,and underwater smart textiles.