01931nas a2200169   4500008004100000022001400041245008900055210006900144260011000213300001400323490000800337520123800345100001601583700002001599700001901619856012301638       2012                        eng d  a0003-265400aUltra-low level optical detection of mercuric ions using biogenic gold nanotriangles0 aUltralow level optical detection of mercuric ions using biogenic  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAPR  a3083-30900 v1373 a<p>Mercury is a serious environmental pollutant known to have detrimental health effects in all life forms. Here, we report the use of biologically synthesized aqueous gold nanotriangles for sensitive and selective optical detection of femto-molar levels of mercury ions by exploiting the high amalgamation tendency of mercury metal towards gold. Aqueous chloroaurate ions were reduced using lemongrass (Cymbopogon flexuosus) leaf extract at room temperature to form gold nanotriangles. Mercuric (Hg2+) ions were reduced in the presence of these triangles to facilitate amalgamation and the optical properties were monitored. We observe a significant change in the longitudinal plasmon absorption band of the nanotriangles even at femto-molar concentrations of mercuric ions. High-resolution transmission electron microscopy confirms changes in particle morphology at such low concentrations. This protocol shows no sensitivity to other environmentally relevant metal ions, including Pb2+, Zn2+, Cd2+, Fe2+, Ni2+, Sr2+, Ca2+, Mn2+, and Cu2+, confirming further that change in the optical properties of gold nanotriangles in the presence of reduced mercuric ions is solely due to the strong amalgamation tendency of mercury metal.</p>1 aSingh, Amit1 aPasrichax, Renu1 aSastry, Murali  uhttps://library.ncl.res.in/content/ultra-low-level-optical-detection-mercuric-ions-using-biogenic-gold-nanotriangles-0