Biosynthesis of silver nanoparticles using nanocurcumin extracted from fresh turmeric of Vietnam

Abstract

This study presents a novel process to synthesize curcumin nanoparticles from fresh turmeric. An ultrasonic-assisted cajeput oil in water emulsion technique was used to synthesize nanocurcumin. The prepared nanocurcumin was spherical with an average size of 47 nm and size distribution of 5–80 nm. The synthesized nanocurcumin showed improved aqueous-phase solubility, and it was used as a reducing agent and stabilizer for biosynthesizing silver nanoparticles. Furthermore, the X-ray diffraction pattern of the silver nanoparticles showed four distinct diffraction peaks at 38.3°, 44.6°, 65.1°, and 78.1° corresponding to the lattice planes of face-centered cubic silver ((111), (200), (220), and (311)). Transmission electron microscopy analysis indicated the average size and maximum size distribution (80 %) of the silver nanoparticles were 10.9 nm and 5–15 nm, respectively. UV–visible spectroscopy measurement of samples indicated the localized surface plasmon resonance absorbance of an aqueous dispersion of silver nanoparticles at 406 nm. Zeta potential analysis revealed a negative charge with a magnitude of −27.2 mV, which indicated higher aqueous dispersion stability of the silver nanoparticles prepared from nanocurcumin. The nanoparticles showed antibacterial activity against Vibrio parahaemolyticus.

Synthesis of Biodegradable and Antimicrobial Nanocomposite Films Reinforced for Coffee and Agri-Food Product Preservation

“…The formation of nanocurcumin was confirmed through ultraviolet–visible (UV–vis) spectral analysis (Figure A). The synthesized nanocurcumin features a strong absorption peak at 424 nm and a small shoulder peak at 447 nm . According to the research results of Subhan et al, the UV–vis spectra of the curcumin solution have a maximum absorption band at wavelength 424 nm and a shoulder near 460 nm, similar to that reported by Moghaddasi et al However, when the AgNO 3 solution reacted with the curcumin solution, C -AgNPs were formed, and the UV–vis absorption spectra of C -AgNPs localized at 408 nm (Figure B) attributed to surface plasmon resonance .…”

“…The formation of C -AgNPs using nanocurcumin solution (Figure ) can explain that the Ag + ions were reduced into Ag° nanoparticles by nanocurcumin through the reaction following the equation Ag false( aq false) + + curcumin ⁢ 0.25em ultrasonic ⁢ energy → false[ Ag ( c urcumin ) false] + false[ Ag ( c urcumin ) false] + + R − CHO ⁢ ultrasonic ⁢ energy → [ Ag false( normalc urcumin false) ] + R − COOH where Ag (aq) + reacted with curcumin solution to form the [Ag(Curcumin)] + complex (eq ), which reacted with numerous functional groups in the molecular structure of curcumin solution as hydroxyl, carboxyl, amine, and aromatic, to form [Ag(Curcumin)], due to the reduction of Ag + ions through the oxidation of the aldehyde to carboxylic acid groups (eq ) as reported in another work . The formation of nanocurcumin was confirmed through ultraviolet–visible (UV–vis) spectral analysis (Figure A).…”

“…The procedure for synthesizing silver nanoparticles was adopted from another study as shown in Figure . The fresh turmeric was cut, polished, dried, and ground to obtain turmeric powder (Figure A).…”

“…The serious environmental problems associated with nonbiodegradability of synthetic polymer films has driven research on edible biopolymer films and coatings to replace synthetic polymers for food packaging materials. , Recently, there has been increasing interest in the development of polymers of natural origin, namely, biopolymers, due to their low toxicity and biodegradable nature. , The combination of biopolymers and nanoparticles, e.g., metal-based or polymeric materials with antimicrobial properties, i.e., alginate, nanocurcumin, and chitosan, has led to an increase in the value and efficiency in the food preservation industry or optoelectronic devices . Current studies , have reported that the integration of silver nanoparticles with other compounds has strong synergistic antimicrobial effects. Polymeric nanoparticles, such as alginate, nanocurcumin, and chitosan, also show antimicrobial activities .…”

“…In this work, we fabricated nanocomposite films using silver nanoparticles synthesized from a nanocurcumin solution (adapted from other processes), chitosan, cassava starch, and PVA. These nanocomposite films were then tested as preservative materials for agricultural and food products (coffee beans, bamboo straws, and fruits) to inhibit bacterial and fungal growth.…”