Microwave-Assisted Green Synthesis of Small Gold Nanoparticles Using Aqueous Garlic (Allium sativum) Extract: Their Application as Antibiotic Carriers

ABSTRACT This article establishes a rapid, microwave-assisted green synthetic method for the production of gold nanoparticles (AuNPs) using garlic extract as a reducing and stabilizing agent and seeks their application as antibiotic carriers. The appearance, crystalline nature, size, and shape of nanoparticles are understood by different physical techniques like UV-vis spectroscopy, transmission electron microscopy, and X-ray diffraction. The AuNPs of size varying from 1.8 ± 0.85 nm to 23.2 ± 4.1 nm were synthesized successfully by varying the power of microwave irradiation. Further, AuNPs (of size 23.2 ± 4.1 nm) were functionalized with ciprofloxacin (cfH), a broad-spectrum antibiotic. A red shift in absorption and emission maxima with decreased intensity suggested successful binding of cfH to AuNPs. AuNPs-conjugated cfH (cfH@AuNPs) were found to have better antibacterial activities in terms of zone of inhibition compared to free cfH against the tested bacterial strains.