Golf ball-like polymer particles with site-selective functionalization of concave and convex regions

Golf ball-like polymer particles, characterized by their distinctive concave–convex surface morphology, have been used as catalyst supports and coating materials owing to their high specific surface area and shape-derived properties. However, site-selective surface functionalization and postsynthetic incorporation of additional functionalities have rarely been investigated. In this study, golf ball-like polymer particles bearing distinct functional groups on their convex and concave regions were fabricated via seeded dispersion polymerization in the presence of n-dodecane droplets. The resulting particles exhibited poly(ethylene glycol) groups on the convex regions, which suppressed nonspecific protein adsorption, while anionic carboxyl groups were localized on the concave regions, enabling electrostatic protein adsorption. Confocal laser scanning microscopy showed that fluorescence from FITC-conjugated proteins was selectively localized to the concave regions, confirming successful site-selective functionalization. Furthermore, metal–organic frameworks (MOFs) were synthesized on the concave surfaces via the carboxyl groups of the particles. These results demonstrate that golf ball-like polymer particles are promising candidates for highly sensitive and selective biosensing applications and serve as a versatile platform for constructing MOF–polymer hybrid materials, thereby considerably expanding the applicability of nonspherical polymer particles.