LAUSR

Sensor‐integrated wound dressings are emerging tools applicable to a wide variety of medical applications from emergency triage to at‐home monitoring. Uncomfortable, unnecessary wound dressing changes may be avoided by providing quantitative insight into tissue characteristics related to wound healing such as tissue oxygenation, pH, and exudate/transudate volume. Here, a simple cost‐effective methodology for quantifying oxygen and pH in a swellable hydrogel dressing using a single photograph is presented. The red and green luminescence of a novel dendritic polyamine Pt‐porphyrin and fluorescein conjugate quantitatively responds to oxygen and pH, respectively, and enables robust sensing. The porphyrin conjugate, when combined with a four‐arm star polyethylene glycol (PEG) amine polymer, rapidly crosslinks at room temperature with an N‐hydroxysuccinimide (NHS)‐PEG crosslinker to form a color‐changing hydrogel dressing with tunable swelling capabilities applicable to a variety of wound environments. An inexpensive digital single‐lens reflex (DSLR) camera modified with bandpass filters captures the hydrogel luminescence using simple macroscopic photography, and conversion to HSB colorspace allows for intensity‐independent image analysis of the hydrogels' dual modality response. The hydrogel formulation exhibits a robust and validated visible red‐orange‐green “traffic light” spectrum in response to oxygen changes, regardless of swelling state, pH, or autofluorescence from skin, thereby enabling the clinician friendly naked‐eye feedback.