Evaluation of biogenic bismuth oxide nanoparticles from Rubus niveus leaves and fruits extract for antimicrobial and photocatalytic activity

[Display omitted] •Bi2O3 NPs demonstrated significant antimicrobial activity against MDR strains, with a 26.5 ± 0.57 mm inhibition zone against MDR P. aeruginosa.•RNF NPs employ a “Nano blade/knife” mechanism to effectively kill MDR strains like P. aeruginosa and fungi such as R. necatrix.•Bi2O3 NPs function as an “Antibiofilm maker,” driving fungi towards stress and a planktonic state.•RNF NPs achieved 94.44 % photodegradation efficiency of malachite dye within 90 min. The present study focused on producing bismuth oxide nanoparticles (Bi2O3 NPs) using methanolic extracts from Rubus niveus fruits and leaves. These extracts were used as both a capping and reducing agent. The properties of the Bi2O3 NPs were determined using advanced characterization methods such as XRD, FTIR, SEM, TEM, XPS, and UV–Vis spectroscopy. The findings demonstrated the formation of spherical and rod-shaped structures in Bi2O3 nanoparticles synthesized using methanol extracts derived from leaves and fruits, respectively. The average diameters of the crystallites were measured as 69.39 nm for RNF-NPs and 62.85 nm for RNL-NPs in Bi2O3 nanoparticles. The grain sizes were observed to be 130 ± 0.25 nm for RNF-NPs and 320 ± 1.22 nm for RNL-NPs, with corresponding D-spacings of 0.314 nm and 0.617 nm. Additionally, the presence of a weak band in the FTIR spectra at 717.29 cm−1 for RNL-NPs and 715.25 cm−1 for RNF-NPs indicated the monoclinic morphology of the synthesized α-Bi2O3 nanoparticles. The antibacterial activity of the samples was assessed using the agar well diffusion technique for bacteria and the poisoned food method for fungus. The antibacterial findings demonstrate that the nanoparticles derived from the methanolic extract of leaves (Methicillin resistance S. aureus [ZOI: 23 ± 0.57 mm] and fruits (MDR P. aeruginosa [ZOI: 26.5 ± 0.57 mm]) exhibit comparable zone of inhibition against multi-drug resistant pathogens. Moreover, the antifungal efficacy of Bi2O3 nanoparticles derived from the methanol extract of the fruits (R. necatrix [59.29 ± 0.80 %]) was shown to be superior to that of nanoparticles obtained from the methanol extract of the leaves. Addition, the methanol extract of the flower demonstrated a superior photocatalytic activity, specifically 94.44 %, using Bi2O3 nanoparticles.