Synthesis of Aloe vera-conjugated silver nanoparticles for use against multidrug-resistant microorganisms

Abstract

Background: The emergence of multidrug-resistant (MDR) microorganisms is one of the biggest and most challenging public health issues drawing considerable attention of the scientific community. Here, we present an easy, one-step, inexpensive and ecofriendly/biologically mediated synthesis of Aloe vera-conjugated silver nanoparticles (Av-AgNPs) where the aqueous plant extract acts as a reducing and stabilizing agent and the resultant conjugate exhibits remarkable potential to limit/inhibit the growth of MDR pathogens.

Results: The nanosynthesis concluded in 4–6 h at 65°C and was followed by detailed characterization of the bioconjugated Av-AgNPs (with and without fabrication on cellulosic materials i.e., cotton fabric and filter paper) using a combination of UV–visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), x-ray diffraction (XRD) and inductively coupled plasma optical emission spectroscopy (ICP-OES). The so-characterized NPs showed growth inhibitory effects on multiple strains including the Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli (E. coli), Acinetobacter baumannii (A. baumannii), Pseudomonas aeruginosa (P. pseudomonas) and, more importantly, the fungus Candida albicans (C. albicans), when analyzed using the Kirby-Bauer method. A notable reduction in the colony-forming unit (CFU) counts of the E. coli (present in contaminated drinking water) was also observed when the filter paper encrusted with Av-AgNPs was applied as a filtration material.

Conclusions: In conclusion, the biofabricated Av-AgNPs are easy to synthesize and are a cost-effective alternative to inorganic AgNPs, with considerable antimicrobial activity, deserving further investigations for biomedical applications.