Polyethylene glycol functionalised Ag NPs based optical probe for the selective and sensitive detection of Hg(II)

The development of more accurate and effective system for the mercury detection is paramount to overcome severe health issues and environmental toxicity. The current investigation reports a highly sensitive technique for rapid colorimetric Hg(II) detection from environmental aqueous samples using Ag NPs functionalised with polyethylene glycol (PEG) in presence of arginine (arg). Ag NPs were characterised by TEM, EDS, UV–visible spectrophotometer, zeta analyser, FT-IR analysis, particle size analyser and XRD. PEG functionalised particles showed zeta potential of 32.32 ± 4 mV. The effective size of NPs was 11 ± 1.4 nm. The yellowish brown colour of the particles were changed to colourless instantly upon Hg(II) addition in arg presence. Excellent linear relationship (y = −0.0021x + 1.3943, correlation co-efficient R2 = 0.9836) was found between absorbance at 396 nm and 20 to 100 nM dilutions of Hg(II). The impact of salinity, pH and temperature on detection of Hg(II) was also performed. Gel and Paper strip were developed which showed highly specific colorimetric detection towards Hg(II). The reported probe can be applied for colorimetric detection and estimation of Hg(II) present in aqueous samples at nano molar level.