Green Synthesis of SnO2/Carbon Quantum Dots Nanocomposite for Gas Sensing Application

SnO2/Carbon Quantum Dots (CQDs) were synthesized by a hydrothermal method using grape fruit juice. The nanocomposites (NC) were characterized by means of XRD and Gas sensing properties. The sensor devices were fabricated using SnO2/CQDs NC as sensing materials. The effect of the CQDs content on the gas-sensing responses and the gas-sensing selectivity was investigated. In this work, the gas sensor developed is exposed to carbon monoxide polluting gas like at different temperatures to determine the optimum operating temperatures which allow obtaining the highest sensitivity for gas. Keywords: Green synthesis, Grape fruit, SnO2 nanoparticles, CQDs, Gas sensor.

Natural synthesis of silver nanoparticles from grape fruit juice and estimation of antimicrobial activity

Silver has been known for its antimicrobial activity for a very long time. Formulation of silver particles that range from 1-100nm in size makes it even more potent to induce antimicrobial effect. Green chemistry has started to become more frequent in the field of biochemical research. Silver nanoparticles synthesized from green synthesis method provide a cheap and environmental friendly method of nanoparticle preparation. The aim of the current study is green synthesis of silver nanoparticles using tomato juice as reducing and capping agent and evaluation of its antimicrobial activity. The stability and conformation of SNPs was determined by UV-visible spectroscopy. The antimicrobial activity of synthesized SNPs was determined against E.coli DH5α. Ultraviolet spectroscopic analysis offered peak at 400 nm that indicate the production of SNPs of adequate size. E.coli DH5α showed considerable decrease upon introduction of SNPs to the bacterial inoculum. Upon increasing the concentration of silver nanoparticles an increase in zone of inhibition was recorded. For 70µg/ml of SNPs, the zone of inhibition was 0.5 cm, while 0.6 cm, 0.7 cm and 0.7cm was recorded for 100µg/ml, 150µg/ml and 200µg/ml of SNPs respectively. The efficacy of antimicrobial activity of SNPs derived from tomato juice proves its potential use in pharmaceutical and medicinal industries for synthesis of nanomedicine.

Burmese grape fruit juice can trigger the “logic gate”-like colorimetric sensing behavior of Ag nanoparticles towards toxic metal ions

Ag NPs synthesized by Burmese grape fruit juice showed selective Hg2+sensing activity.