Abroma augusta Linn bark extract-mediated green synthesis of gold nanoparticles and its application in catalytic reduction

Subhajit Das,Braja Gopal Bag,Ranadhir Basu

doi:10.1007/s13204-014-0384-4

Subhajit Das, Braja Gopal Bag + Show 1 more

Open Access

https://doi.org/10.1007/s13204-014-0384-4

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Abstract

The bark extract of Abroma augusta Linn is rich in medicinally important phytochemicals including antioxidants and polyphenols. First one step green synthesis of gold nanoparticles (AuNPs) has been described utilizing the bark extract of Abroma augusta L. and chloroauric acid under very mild reaction conditions. The phytochemicals present in the bark extract acted both as a reducing as well as a stabilizing agent, and no additional stabilizing and capping agents were needed. Detailed characterizations of the stabilized AuNPs were carried out by surface plasmon resonance spectroscopy, high resolution transmission electron microscopy, and X-ray diffraction studies. The catalytic activity of the freshly synthesized gold nanoparticles has been demonstrated for the sodium borohydride reduction of 4-nitrophenol to 4-aminophenol, and the kinetics of the reduction reaction have been studied spectrophotometrically.

Highlights

Gold nanoparticles (AuNPs) with unique optical, electronic, and magnetic properties have drawn tremendous research interests during the last two decades (Alkilany et al 2013, Zhang et al 2012) because of their applications in diversified areas such as catalysis (Wittstock and Baumer 2014; Liu et al 2014) drug delivery, biodiagnostics (Murphy et al 2008), medical imaging (Huang et al 2009), plasmonics (Pelton et al 2008), and chemical sensing
Realizing the roles of free radicals and active oxygen species as the cause of various physiological disorders including cancer and tumors, we examined the presence of antioxidants in the bark extract of Abroma augusta L. against a long lived 2, 2-diphenylpicrylhydrazyl (DPPH) radical at room temperature
The phytochemicals present in the bark extract of Abroma augusta L. has been utilized for the green synthesis of colloidal gold nanoparticles in water at room temperature

Summary

Introduction

Gold nanoparticles (AuNPs) with unique optical, electronic, and magnetic properties have drawn tremendous research interests during the last two decades (Alkilany et al 2013, Zhang et al 2012) because of their applications in diversified areas such as catalysis (Wittstock and Baumer 2014; Liu et al 2014) drug delivery, biodiagnostics (Murphy et al 2008), medical imaging (Huang et al 2009), plasmonics (Pelton et al 2008), and chemical sensing. AuNPs dispersed in water and stabilized with non-toxic biomolecules are required for many of such applications. Among various methods reported for the synthesis of AuNPs, the plant extract-mediated reductive method, involving the reduction of Au(III) to Au(0) by the phytochemicals, has gained profound significance in recent years due to the renewable and non-toxic nature of the phytochemicals, mild reaction conditions, eco-friendly aqueous medium, etc. The green synthesis of AuNPs from the extracts of Macrotyloma uniflorum (Aromal et al 2012), Trigonella foenum-graecum (Aromal and Philip 2012), Aloe vera (Chandran et al 2006), Acacia nilotica leaf (Majumdar et al 2013), Saraca indica bark (Dash et al 2014), Punica granatum (Dash and Bag 2014), Green coconut shell (Paul et al 2014), etc., has been reported (Mittal et al 2013). Due to rapid emergence of newer applications of nanoparticles and nanomaterials, there is an ever growing need for the development of newer methods for the synthesis of metal nanoparticles utilizing plant resources as renewables

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