The erratum for the article "Antibacterial properties of nanoparticles" by Hajipour et al. (Trends in Biotechnology, 2012) addresses errors in Figures 3 and 4. Figure 3 illustrates the toxicology effect of multifunctional nanoparticles (NPs) in bacterial biofilms, showing that silver ring-coated and gold-coated superparamagnetic iron oxide NPs (SPIONs) have strong toxic effects by penetrating biofilms and inducing heat through magnetic and laser fields. Figure 4 explains the mechanisms of NP toxicity against bacteria, highlighting how NPs and their ions (e.g., silver and zinc) produce free radicals, leading to oxidative stress and irreversible bacterial damage. The authors apologize for these errors.The erratum for the article "Antibacterial properties of nanoparticles" by Hajipour et al. (Trends in Biotechnology, 2012) addresses errors in Figures 3 and 4. Figure 3 illustrates the toxicology effect of multifunctional nanoparticles (NPs) in bacterial biofilms, showing that silver ring-coated and gold-coated superparamagnetic iron oxide NPs (SPIONs) have strong toxic effects by penetrating biofilms and inducing heat through magnetic and laser fields. Figure 4 explains the mechanisms of NP toxicity against bacteria, highlighting how NPs and their ions (e.g., silver and zinc) produce free radicals, leading to oxidative stress and irreversible bacterial damage. The authors apologize for these errors.