A new bandage material was engineered to improve the treatment of bacterial infections by quickly detecting the presence of antibiotic-resistant microbes. The material formulated by Chinese Academy of Sciences researchers changes color when an infection or drug-resistant bacteria is detected and administers drugs accordingly.

The paper-based bandage changes color from green to yellow when in proximity to the acidic microenvironment of a bacterial infection and releases an antibiotic that kills drug-sensitive bacteria. The antibiotic ampicillin is loaded into nanomaterials that dissolve under acidic conditions and releases the drugs.

If drug-resistant bacteria are present, the bandage turns red in color due to an enzyme produced by these The bandage changes from a green color to yellow, indicating bacterial infection, or to red, signaling drug resistance. Source: Y. Sun et al.microbes. In this situation, shining a light on the bandage induces the material to release reactive oxygen species (ROS) that kill or weaken the bacteria, making them more susceptible to the antibiotic.

The cellulose paper incorporates a porphyrin-based metal–organic framework (MOF) that has the desired photodynamic therapy properties. Under light exposure, the MOF yields the ROS that deactivate antibiotic-resistant agents.

As reported in ACS Central Science, the bandage performed as designed when applied to wounds in mice infected with drug-sensitive or drug-resistant Escherichia coli. The color change and subsequent release of therapeutic agents were observed to occur within two to four hours, and the limit of detection was 104 colony forming units/ml for drug-resistant E. coli, which meets the need for clinical diagnosis.