Eco-friendly synthesis of N- cholyl mercapto histidine capped silver nanoparticles and its sensing of mercury (II) ions and photo catalytic degradation of methyl orange.

In this report, we have developed highly water soluble and stable silver nanoparticles (Ag NPs) utilizing N-Cholyl Mercapto Histidine (NCMH) as a reducing and stabilizing agent with near the primary critical micellar concentration (CMC) under ambient sunlight irradiation. Moreover, The NCMH was firstly synthesized by demonstrating the reaction between cholic acid and 2- Mercapto Histidine through a simple acid amine coupling approach. The primary and secondary CMC of NCMH surfactant was measured by pyrene (1 × 10 M) as a fluorescent probe, and values were found to be 3.2 and 13.1 mM respectively. The synthesized Ag NPs showed at neutral pH and highly stable for more than one year without any noticeable aggregation. The TEM analysis displays the synthesized Ag NPs having a spherical shape and average size of 9.6 ± 0.5 nm. The synthesis of stabilized Ag NPs was used for ultra-sensitive and selective detection of Hg ions in aqueous medium were monitored by Uv-visible spectrometer and naked eyes with a lowest limit of detection (LOD) 7 nM. The photo-catalytic degradation of methyl orange (MO) by utilizing Ag NPs as nano-catalyst exhibits a potential degradation within a study period of 180 min. Concluding that, facile and cost effective green synthesis of NCMH capped Ag NPs possess excellent reducing ability towards the selective detection of Hg ions along with photo-catalytic degradation of MO dye. These true findings detached an innovative pathway of Ag NPs towards the reactivity against the catalytic activity of dye degradation and selective sensing of Hg ions. Thus it paves the way for extensive range of novel potential applications of Ag NPs in various environment friendly approaches of sensitive and analytical protocol in the future.