Biomedical Applications of Cocoa Bean Extract-Mediated Silver Nanoparticles as Antimicrobial, Larvicidal and Anticoagulant Agents

In this work, cocoa bean extract (CBE) was used to synthesize silver nanoparticles (AgNPs) under ambient conditions. The fairly polydispersed spherical CBE-AgNPs had size range of 8.96-54.22 nm with lambda max occurring at 438.5 nm. The prominent peaks at 3275.13 and 1635.54 cm(-1) from FTIR data laid credence to the involvement of phenolics and proteins in the biofabrication and stabilization of CBE-AgNPs. Energy dispersive X-ray and selected area electron diffraction studies showed the conspicuous presence of silver in colloidal solution with distinctive crystalline face-centered cubic phase of AgNPs. CBE-AgNPs showed appreciable activities against multi-drug resistant bacteria, producing zones of inhibition of 10-14 mm, and also enhanced activities of ampicillin, cefuroxime, cefixime and erythromycin by 42.9-100 % in synergistic studies. It produced pronounced antimicrobial activities against several bacteria and fungi, when incorporated into emulsion paint. Furthermore CBE-AgNPs showed good larvicidal activities against Anopheles gambiae mosquito larvae with LC50 of 44.37 A mu g/ml, while it also prevented the coagulation of human blood. This study established synthesis of AgNPs using CBE as a viable green route approach, with remarkable antimicrobial, larvicidal and anticoagulant activities. As far as we know, this is the first report of the use of CBE to synthesize AgNPs. [GRAPHICS] .