Nanosilver Synthesis of Bromelain Isolate from Pineapple Extract: A Green Approach for Antibacterial Applications

Abstract

Introduction: Silver nanoparticle technology has high bactericidal activity because silver ions can affect bacterial cell death, as well as nanoparticle size, which can increase drug bioavailability.

Objectives: This study aims to synthesize and characterize silver nanoparticles from bromelain isolate of pineapple fruit and test the antibacterial activity of silver nanoparticles.

Methods: Isolation was carried out to obtain bromelain enzyme isolates; isolates were tested for calculating bromelain content by spectrophotometry. The biosynthesis of silver nanoparticles was made by varying the number of isolates, silver nitrate solution, and PVA by ultrasonication method. Furthermore, characterization was carried out by visual observation, observation of wavelength, determination of particle size, polydispersity index, zeta potential, determination of functional groups by FTIR, and morphological evaluation by SEM. Then, the antibacterial activity of the diffusion method was tested against Staphylococcus aureus bacteria, and five formulations were obtained.

Results: The formation of nanoparticles was characterized by a change from colourless to brownish yellow, a wavelength of 537.0 nm, and an absorbance of 1.276. The particle size was 92.90 nm ± 1.15, the polydispersity index value was 0.379±0.028, and the zeta potential was –38.8 mV ± 0.64. The functional group formed indicates –OH, C=O, and N=O at wave numbers 3325.04, 1634.55, and 1370.06 cm^-1. It has a uniform cuboidal morphology. The results of the antibacterial activity test showed a clean and clear inhibition zone of 13.7 mm ± 1.5 against Staphylococcus aureus bacteria.

Conclusions: Silver nanoparticles synthesized by bromelain isolate of pineapple fruit have the requirements for suitable silver nanoparticles and have antibacterial activity.