Biosynthesized gold nanoparticles-doped hydroxyapatite as antibacterial and antioxidant nanocomposite

Abstract

The composite of green synthesized gold nanoparticles (Au NPs)-doped hydroxyapatite (HA) has been prepared. The gold nanoparticles were produced via bioreduction of HAuCl4 with Clitoria ternatea flower extract, and utilized in the synthesis of hydroxyapatite using Ca(OH)2 and ammonium diphosphate as precursor. The aim of this research is to study the structural analysis of the composite and antibacterial activity test toward Eschericia coli, Staphylococcus aureus, Klebsiela pneumoniae, and Streptococcus pyogenes. In addition, the antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The monitoring of gold nanoparticles formation was conducted by UV–vis spectroscopy and particle size analyses, meanwhile the synthesized composite was studied using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that homogeneously dispersed gold nanoparticles in HA structure was obtained with the particle size ranging at 5-80 nm. The nanocomposite demonstrated antibacterial activity against tested bacteria. The nanocomposite expressed an antioxidant activity as shown by the DPPH scavenging activity of 66 and 58% at the concentration of 100 μg/mL and 50 μg/mL, respectively.

Exploring the biomedical competency of gamma-radiation aided hydroxyapatite and its composite fabricated with nano-cellulose and chitosan

“…The radical solution alone was used as control while the test sample was prepared by adding γ-radiated Hap with DPPH solution. Using the measured absorbance at 515 nm, the ability of γ-radiated Hap to scavenge the DPPH radical was calculated with the aid of the following eqn (2): 35,36 where A c and A s signifies the absorbance of the control and test samples, respectively.…”

“…To evaluate the antioxidant activity of g-radiated Hap, 2,2diphenyl-1-picrylhydrazyle (DPPH) free radical scavenging method [34][35][36][37] was adapted. The radical solution alone was used as control while the test sample was prepared by adding g-radiated Hap with DPPH solution.…”

Photothermal Conversion Efficiency of Silver and Gold Incorporated Nanosized Apatites for Biomedical Applications

“…Over the last few years, hydroxyapatites doped as well as codoped with silver and gold ions have been developed. − They have improved antibacterial properties and can be used for theranostics. Moreover, the doping of hydroxyapatite with noble metals can open a new possibility for its application in diseases that are treated with photothermal therapy.…”