Two-step biocompatible surface functionalization for two-pathway antimicrobial action against Gram-positive bacteria.

•The development of a simple two-steps protocol to multi-functionalize Ti surfaces was achieved.•Two antimicrobial agents, ampicillin and AgNPs, were immobilized on Ti/TiO2 surfaces.•The surface chemistry for the anchoring of both agents was established for the first time.•Adsorbed ampicillin and AgNPs are able to kill sessile S. aureus.•The multi-functionalized Ti surfaces are able to keep the antimicrobial capacity over time.