Spinach-extracted chlorophyll-a modified peanut shell as fluorescence sensors for selective detection of Hg2+ in water

A prototype of environmentally friendly and low-cost fluorescence sensor, consisting of spinach-extracted chlorophyll- a modified alkali-treated peanut shell (denoted as chlorophyll- a @peanut shell), is achieved and used for trace detection of Hg 2+ in aqueous solutions through fluorescence quenching method. The chlorophyll- a @peanut shell exhibits a linear dynamic detection range from 0 to 19   ×   10 −8   M for Hg 2+ with a detection lower limit of 8.5   ×   10 −9   M. The feasibility of sensitive and selective detection of Hg 2+ using the chlorophyll- a @peanut shell is also demonstrated in the test of Hg 2+ in synthetic polluted lake waters, showing excellent anti-interference ability to common impurities like silt and alga. Further experiments demonstrate that the improved sensing property of the chlorophyll- a @peanut shell for Hg 2+ than that of chlorophyll- a in solution is ascribed to the selective Hg 2+ adsorption of the alkali-treated peanut shell, which might also be used for the remediation of Hg 2+ in polluted waters. The design concept using non-toxic plants may open a new door to the environmentally friendly and low-cost materials for detection and remediation of environmental pollutants .