Synthesis of Ag nanoparticles in Span/Span-Tween mixed surfactant system and its optical, kinetic and fluorimetric studies

• Span and Span-Tween mixed surfactant system stabilizes Ag nanoparticle synthesized chemically and photochemically.
• Different shaped Ag nanoparticles exhibit optical property.
• Ag nanoparticles catalyses electron transfer rate process between CoIII and FeII about 8 times.
• Nanoparticles’ size dependent fluorescence quenching property has been rationalized considering its surface area.
• Interaction of Ag nanoparticles with BSA and Hb proves the formation of a ground state BSA-Ag complex.

Span and Span-Tween mixed surfactants have been used to stabilize the silver nanoparticles synthesized chemically and photochemically. This synthetic process of silver sol preparation has the advantage of producing homogeneous particles of very small size (∼1.65 nm) and finally aggregate brilliantly in a symmetric manner to form cubic clusters. Electromagnetic interaction in the close-packed assembly of silver aggregates generates its optical property that has been explained in the light of Maxwell-Garnett effective medium theory. A small sized silver nanoparticle has quenching properties on the fluorophore probes of methylene blue and cresol red. The particle size dependent fluorescence quenching property has been rationalized considering its surface area. Steady state circular dichroism and time resolved spectroscopic studies of Ag nanoparticles with bovine serum albumin (BSA) and human adult hemoglobin (Hb) proves the formation of a ground state BSA-Ag complex. The effect of different sizes of silver nanoparticle on the rate of electron transfer reaction between [CoIII(NH3)5Br](NO3)2 and Mohr's salt (FeII) has also been explained rationally.

Cube shaped Ag nanoparticle has been synthesized both chemically and photochemically using mixtures of Span and Tween surfactant series as capping agent. It has fluorescence quenching property for cresol red. It enhances aggregation of methylene blue. The interaction of colloidal Ag nanoparticles with bovine serum albumin (BSA) and human adult hemoglobin (Hb) has been explained rationally.Figure optionsDownload as PowerPoint slide