Virus-like Cu₇S₄/vSiO₂/TA micromotors for localized bacterial capture and synergistic photothermal therapy

The escalating threat of antibiotic-resistant bacterial infections necessitates innovative antimicrobial strategies beyond conventional approaches. Micro/nanomotors, leveraging self-propulsion and intrinsic antibacterial capabilities, offer a promising alternative. However, existing bactericidal micromotors face a fundamental trade-off between motility and bacterial capture capacity. To address this challenge, we synthesized rough-surfaced, virus-like Cu₇S₄/vSiO₂/TA micromotors for localized bacterial capture and synergistic photothermal therapy. This multifunctional platform integrates: i) Cu₇S₄ nanoparticles as a high-efficiency NIR photothermal core (λ = 1064 nm), ii) virus-like silica (vSiO₂) shells engineered with nanospike structures to mimic viral morphology, enabling multivalent, affinity-driven bacterial capture, iii) Tannic acid (TA) coatings providing robust adhesion functionality and enhanced biocompatibility. Attributed to these intriguing properties, the micromotors exploit NIR-II light-fueled self-propulsion to actively seek and accumulate at infection sites. The vSiO₂/TA surface facilitates targeted bacterial adhesion through synergistic physicochemical interactions, effectively "trapping" pathogens locally. Subsequent NIR irradiation triggers the Cu₇S₄ core to generate rapid, localized hyperthermia (>50 °C), achieving synergistic bacterial eradication while minimizing off-target damage. We demonstrate the micromotors' efficacy against diverse bacterial targets (e.g., Gram-positive/Gram-negative strains), highlighting their potential as a targeted, antibiotic-free strategy for treating localized bacterial infections. We believe that this work pioneers the convergence of biomimetic capture (virus-like topology), autonomous motion, and photothermal conversion within a single platform.