Next‐Generation Wound Care: Aptamer‐Conjugated Polydiacetylene/Polyurethane Nanofibrous Biosensors for Selective In Situ Colorimetric Detection of Pseudomonas

Abstract Biosensors for wound dressings can enable point‐of‐care monitoring of wound bed health by exhibiting a color change visible to the naked eye, to alert healthcare providers of the presence of pathogenic bacteria. Here, a polydiacetylene‐based electrospun nanofibrous wound dressing for the detection of Pseudomonas aeruginosa is reported. Using conventional blend electrospinning, two diacetylene monomers—10,12‐pentacosadiynoic acid (PCDA) and 10,12‐tricosadiynoic acid (TCDA)—are separately electrospun alongside polyurethane as a supporting matrix polymer. The differences in side‐chain length impact the sensitivity of the nanofibers in detecting P. aeruginosa . Furthermore, two DNA aptamers are conjugated to the polydiacetylenes to achieve targeted detection of P. aeruginosa . The aptamer‐modified dressings show improved sensitivity of detection toward eight strains of P. aeruginosa compared to the unmodified membranes. Furthermore, the aptamer‐modified membranes do not respond to non‐target bacteria methicillin‐resistant Staphylococcus aureus (MRSA), Staphylococcus aureus , and Escherichia coli within 3 h of direct contact. Reducing the chain‐length of the diacetylene monomer by substituting PCDA with TCDA boosts the colorimetric response by a factor of >2x compared to the aptamer‐modified PCDA membranes, at the cost of reduced specificity. The aptamer‐conjugated polydiacetylene membranes show promise for application in point‐of‐care wound dressings for improved specificity of detection of bacterial infections.