Tripodal pyridyl-imine capped gold nano-aggregates for selective detection of picric acid in aqueous media

Abstract

In the present investigation, we have design and develop pyridyl-imine capped gold nanoaggregates; fully characterized via various spectroscopic techniques. The photophysical and electrochemical studies revealed that the developed pyridyl-imine capped gold nanoaggregates are proven to be selective sensor for picric acid with remarkable low detection limit within nano-molar concentration (15.0 nM) based on 3σ/K; a common constituent of many powerful explosives. The quenching of fluorescence intensity at λ 357 nm occurs which may ascribe to the electron transfer phenomenon exhibited by the electron rich receptor and emergence of red shift in fluorescence spectroscopy (λem 464 nm) after gradual addition of picric acid; a selective phenomenon towards the most electron deficient nitroaromatic (picric acid) sensing. Additionally, the results obtained for the analysis of spiked samples in real water samples such as river and tap water, show that the developed PA sensor is potentially applicable in the determination of trace PA explosive without any interference.