Hybrid poly(dopamine/phenosafranin) microparticles as replicas of yeast capsules for the immobilization of myoglobin

Yeast capsules (YCs) were loaded with a photosensitive phenosafranin (PSF) dye through electrostatic force-driven spontaneous deposition and served as templates for synthesizing biocompatible microparticles. Oppositely charged dopamine and PSF were encapsulated and deposited onto the yeast polysaccharide scaffold through ionic complexation. Subsequently, self-oxidative polymerization was carried out in situ, forming YC@(PDPSF) microparticles. To extend an innovative idea for diverse design and multipurpose YC@(PDPSF) applications, we immobilized myoglobin (Mb) on their surface. The multifunctional coating facilitated the immobilization of Mb involved in oxygen (O₂) storage utilizing the carbodiimide method with 6-aminocaproic acid (ACA) as a linker. The biological activity of Mb encapsulated in YCs and immobilized on the surface of YC@(PDPSF) microparticles was compared using UV–vis spectrophotometry. The assays showed that the catalytic activity of Mb was sufficiently retained after immobilization. This new YC@(PDPSF)-Mb microparticles will have potential applications in biosensors, particularly for detecting and separating specific analytes and small molecules (e.g. NO, CO). Their unique properties could make them valuable for various biomedical purposes including enzyme assays, chromatography, air pollution control devices, and filtration processes in gas mask filters.