A "Test-to-Treat" Pad for Real-Time Visual Monitoring of Bacterial Infection and On-Site Performing Smart Therapy Strategies

Skininfections are major threats to human health, causing & SIM;500incidences per 10 000 person-year. In patients with diabetesmellitus, particularly, skin infections are often accompanied by aslow healing process, amputation, and even death. Timely diagnosisof skin infection strains and on-site therapy are vital in human healthand safety. Herein, a double-layered "test-to-treat"pad is developed for the visual monitoring and selective treatmentof drug-sensitive (DS)/drug-resistant (DR) bacterial infections. Theinner layer (using carrageenan hydrogel as a scaffold) is loaded withbacteria indicators and an acid-responsive drug (Fe-carbenicillinframeworks) for infection detection and DS bacteria inactivation.The outer layer is a mechanoluminescence material (ML, CaZnOS:Mn2+) and visible-light responsive photocatalyst (Pt@TiO2) incorporated elastic polydimethylsiloxane (PDMS). On thebasis of the colorimetric sensing result (yellow for DS-bacterialinfection and red for DR-bacterial infection), a suitable antibacterialstrategy is guided and then performed. Two available bactericidalroutes provided by double pad layers reflect the advantage. The controllableand effective killing of DR bacteria is realized by in situ generated reactive oxygen species (ROSs) from the combination ofPt@TiO2 and ML under mechanical force, avoiding physicallight sources and alleviating off-target side effects of ROS in biomedicaltherapy. As a proof-of-concept, the "test-to-treat"pad is applied as a wearable wound dressing for sensing and selectivelydealing with DS/DR bacterial infections in vitro and in vivo. Thismultifunctional design effectively reduces antibiotic abuse and accelerateswound healing, providing an innovative and promising Band-Aid strategyin point-of-care diagnosis and therapy.