Opportunities for Mercuric Ion Spectrophotometric Determination based on Reduction of Gold Nanoparticles Aggregation by N-containing Cyclic Molecules

Methods for the determination of mercury are described using gold nanoparticles functionalized with nitrogen containing cyclic molecules. Detection methods are based on the prevention of nitrogenous compounds induced aggregation of gold nanoparticles by mercury. Histamine, melamine, o -phenylenediamine and uracil induced aggregation of gold nanoparticles. Incubation of histamine, melamine or o -phenylenediamine with mercury resulted in reduction of gold nanoparticles aggregation. Inverse relationship was observed between mercury concentration and aggregation of gold nanoparticles. Dynamic ranges of the methods using histamine, melamine and o -phenylenediamine were 200 nM–7.5 µM, 200 nM–6.0 µM and 200 nM–2.0 µM, respectively. Metals, namely, Pb(II), Co(II), Cr(III), Cu(II), Ni(II), Zn(II), Ca(II), Ba(II) and Cd(II), did not interfere in the assay. However, Ag(I) prevented histamine and o -phenylenediamine induced aggregation of gold nanoparticles. Histamine, melamine and o -phenylenediamine can serve as ligands for the development of sensitive methods for mercury.