Antioxidant activity of gold nanoparticles using gum arabic as a stabilizing agent

Objectives: The aim of this study is to investigate the effect of gum arabic (GA) as reducing agent and stabilizer in gold nanoparticle (AuNP) formulation and the antioxidant activity of GA-AuNP. Methods: Gold nanoparticles (AuNPs) were synthesized by reducing hydrogen tetrachloroaurate (HAuCl₄) via three techniques: using gum arabic (GA-AuNP), using sodium borohydride (NaBH4) with GA as a stabilizing agent (GA-AuNP), and using NaBH4 (AuNP). These nanoparticles were characterized via UV-VIS spectroscopy, TEM, AFM, and PSA. The antioxidant activity of the AuNPs was measured via the DPPH method. Their physical stability was determined using a UV-VIS spectrophotometer over 5 weeks during storage at room temperature. Results: The AuNPs formed using gum arabic as both the reducing agent and stabilizer, using sodium borohydride as the reducing agent with gum arabic as the stabilizer, and using sodium borohydride alone had particle sizes of 6.52 ± 0.66 nm, 4.045 ± 0.99 nm, and 55.82 ± 39.87 nm, respectively. The percentages oxidation inhibition for these particles were 74.39 ± 0.255%, 73.51 ± 0,251%, and 72.63 ± 0.567%, respectively. Conclusion: Gum arabic (GA) was successfully acted as reducing and stabilizing agent to the gold nanoparticle (AuNP) and increase the percentage oxidation inhibition of AuNP. The stability test indicated that the GA-AuNP were physically stable for at least 5 weeks.