Colorimetric detection of mercury ions from environmental water sample by using 3-(Trimethoxysilyl)propyl methacrylate functionalized Ag NPs-tryptophan nanoconjugate

Recent trend in the nanotechnology made an interest to make nano based system to detect the environmental pollutant including heavy metals, pesticides and antibiotics. Mercury is toxic heavy metals which causes hazardous effect to human and environmental organisms. They usually reach to the environment by mining, petrol refining and coal burning, which can change to its ionic forms according to the environmental condition. The present study was concentrated on the effective detection of Hg (II) ion from environmental sample colorimetrically by developing Ag NPs - tryptophan nanoconjugate functionalized with 3-(Trimethoxysilyl)propyl methacrylate (TMPM). The characterization of prepared particles was performed by UV-visible spectro-photometer, transmission electron microscopy (HRTEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), particle size analyzer and zeta sizer. The size of prepared NPs was 9 +/- 1.10 nm and it possess the surface charge of - 37.41 +/- 4 mV. Upon the interaction of Ag NPs - tryptophan nanoconjugate and Hg (II) ion, the colour of the conjugate disappeared. The effect of environmental factors (Temperature, pH and saline concentration) on Hg (II) ion detection was also investigated. The probe indicated that Ag NPs - tryptophan nanoconjugate functionalized with TMPM was found to be an efficient tool for mercury detection from various environmental water samples.