In the relentless battle against multidrug-resistant (MDR) bacteria, a team of researchers led by Benjamín Hernández-Figueroa at the Centro de Investigación en Materiales Avanzados in Mexico has made a significant stride. Their work, published in the journal *Applied Surface Science Advances* (translated to English as “Advances in Applied Surface Science”), explores the enhanced antimicrobial activity of magnesium oxide (MgO) nanoparticles through zinc doping. This research could have profound implications for the construction and energy sectors, where bacterial growth can pose serious challenges to infrastructure and human health.
The team synthesized two samples of zinc-doped MgO nanoparticles, with zinc concentrations of 10% and 16%, and compared their properties with a commercial MgO sample. Structural analyses confirmed a cubic structure, which underwent distortions as the zinc concentration increased. Microstructural studies revealed the formation of nanoparticles with a polyhedral morphology, resulting from the surface hydroxylation of cubic-shaped particles.
One of the most intriguing findings was the reduction in bandgap energy from 5.7 eV to 4.7 eV due to the incorporation of zinc and the presence of defects such as oxygen vacancies. “This reduction in bandgap energy suggests that the doped nanoparticles have enhanced electronic properties, which could be crucial for their antimicrobial activity,” explained Hernández-Figueroa.
The antibacterial activity of these nanoparticles was evaluated based on the IC50 value, which is the concentration required to inhibit bacterial growth by 50%. The results were promising. For Staphylococcus aureus ATCC, the IC50 value was reduced from 0.8 mg/mL for commercial MgO nanoparticles to 0.49 mg/mL for the 10% zinc-doped MgO. Even more impressive were the results against multidrug-resistant strains. For S. aureus MDR, the IC50 value dropped from 2.81 mg/mL for commercial MgO to 0.69 mg/mL for the doped nanoparticles.
Similar trends were observed for Pseudomonas aeruginosa, a bacterium known for its resistance to multiple antibiotics. The IC50 value for the commercial MgO nanoparticles was 0.77 mg/mL, which decreased to 0.34 mg/mL for the 10% zinc-doped MgO. For the MDR strain of P. aeruginosa, the IC50 value was less than 0.5 mg/mL for the doped nanoparticles, compared to 0.710 mg/mL for the commercial MgO.
These findings suggest that zinc-doped MgO nanoparticles could be a powerful tool in the fight against multidrug-resistant bacteria. “The enhanced antimicrobial activity of these nanoparticles opens up new possibilities for their use in various applications, including coatings for medical devices, water treatment, and even in the construction industry to prevent bacterial growth on surfaces,” said Hernández-Figueroa.
The potential commercial impacts for the energy sector are also significant. Bacterial growth can lead to biofouling, which can reduce the efficiency of energy systems and increase maintenance costs. The use of antimicrobial coatings based on zinc-doped MgO nanoparticles could help mitigate these issues, leading to more efficient and cost-effective energy systems.
As the world grapples with the growing threat of antibiotic resistance, research like this offers a glimmer of hope. The enhanced antimicrobial activity of zinc-doped MgO nanoparticles represents a promising strategy for combating multidrug-resistant bacteria, and could pave the way for new treatments and preventive measures. With further research and development, these nanoparticles could become a key weapon in our arsenal against the growing threat of antibiotic resistance.