pH-Triggered Visible Indicator Dressing for Early Diagnosis of Bacterial Wound Infection
Cutaneous wound infections affect millions of patients annually worldwide, and early diagnosis is critical for timely anti-infection treatment. Bacterial infections alter wound pH, offering a promising diagnostic approach. Here, a diagnostic smart dressing (CMC-PDBI) is developed by ultraviolet-initiated crosslinking of a pH-responsive indicator coating, incorporating modified bromothymol blue, onto a carboxymethyl cellulose substrate. The dressing exhibits superior pH-triggered color-changing performance in both phosphate buffer solution and bacterial cultures across the pH range associated with wound infection (orange at pH 6.0, green from pH 6.5 to 7.5, blue at pH 8.0). In a murine wound infection model, CMC-PDBI indicates infection two days before symptomatic manifestation. Early therapy guided by the dressing accelerates wound healing and reduces inflammation. A smartphone application (InfectSense) assists in identifying infection risk. This work presents a novel early-warning platform for qualitative visual diagnosis of wound infections before clinical symptom onset, with high potential for clinical and home care settings.