<p>This study introduces an innovative bioconjugation platform utilizing dendritic biofilms as dynamic templates to assemble hollow zinc oxide (ZnO) and silver oxide (Ag₂O) structures on a magnetic sulfonated melamine formaldehyde (MSMF) matrix. This biofilm-assisted synthesis facilitates the formation of sophisticated dendritic and hollow oxide frameworks, significantly enhancing surface area and catalytic performance. The resulting adaptable composites exhibit superior catalytic efficiency, particularly in the Biginelli reaction, highlighting their potential for diverse applications. The two-stage fabrication involves coating iron oxide (Fe₃O₄) particles with sulfated melamine formaldehyde (SMF) to form Fe₃O₄@SMF, followed by dendritic biofilm-mediated assembly for the deposition of hollow ZnO (Fe₃O₄@)SMF@)DBA.ZnO) and Ag₂O (Fe₃O₄@)SMF@)DBA.ZnO.Ag₂O) particles. This innovative approach enables precise control over magnetic and catalytic properties through the integration of hollow, dendritic architectures. Advanced analytical techniques confirm the distinct morphology and structural features achieved by this biofilm-guided process. This novel synthesis enabled the rapid production (30–60 min) of diverse 3,4-dihydropyrimidinone derivatives with high yields (65–95%). Furthermore, the magnetic properties and hierarchical architecture of these catalysts facilitate facile separation and recyclability for at least four cycles without performance decline. This strategic combination of biofilm engineering, hollow frameworks, and magnetic functionality paves the way for next-generation sustainable catalysts with multifunctional applications.</p>