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Synthesis of uniform gold nanoparticles using non-pathogenic bio-control agent: Evolution of morphology from nano-spheres to triangular nanoprisms

Mukherjee, P., Roy, Mainak, Mandal, B.P., Choudhury, Sipra, Tewari, R., Tyagi, A.K., Kale, S.P.
Journal of colloid and interface science 2012 v.367 no.1 pp. 148-152
Trichoderma asperellum, centrifugation, fungi, gold, nanogold, nanoparticles, nanospheres, reaction kinetics, spectroscopy, transmission electron microscopy
Green synthesis of gold nanospheres with uniform diameter and triangular nanoprisms with optically flat surface was carried out using a non-pathogenic bio-control agent Trichoderma asperellum for reduction of HAuCl₄. Kinetics of the reaction was monitored by UV–Vis absorption spectroscopy. No additional capping/complexing agent was used for stabilizing the gold nanoparticles. Evolution of morphology from pseudospherical nanoparticles to triangular nanoprisms was studied by transmission electron microscopy (TEM). It revealed that three or more pseudospheres fused to form nanoprisms of different shapes and sizes. Slow rate of reduction of HAuCl₄ by constituents of cell-free fungal extract was instrumental in producing such exotic morphologies. Isolation of gold nanotriangles from the reacting masses was achieved by differential centrifugation.