Facile Synthesis of Polysulfoaminoanthraquinone Nanosorbents for Rapid Removal and Ultrasensitive Fluorescent Detection of Heavy Metal Ions

Poly(5-sulfo-1-aminoanthraquinone) nanoparticles were facilely synthesized by a chemical oxidative polymerization of 5-sulfo-1-aminoanthraquinone. The polymerization parameters such as oxidant species, acid species, acid concentration, oxidant/monomer ratio, polymerization time, and temperature were systematically studied to significantly optimize the synthetic yield, structure, and multifunctionalities of the target nanoparticles. The molecular structure, size distribution, morphology, and properties of the nanoparticles were detailedly analyzed by R, UV-vis, and fluorescence spectroscopies, element analyses, MALD1-MS, X-ray diffraction, FESEM, AFM, laser particle analyzer, and simultaneous TG/DSC. It is found that K2CrO4 oxidant and aqueous HClO4 without any external stabilizers are an optimal combination for synthesizing the nanoparticles with a clean surface, large pi-conjugation, narrow size distribution, intrinsic semiconductivity, blue fluorescence, and inherent self-stability that is ascribed to many negatively charged sulfonic groups on their macromolecular chains. In particular, the nanoparticles having a unique synergic combination of five kinds of active -NH-, -N=, -NH2, =O, and -SO3H groups with an appropriate specific area of 115.15 m(2) g(-1) exhibit very high removal percentage of respective lead and mercury of 99.6 and 99.8% at initial concentrations of even up to 200 mg L-1, ultrarapid initial adsorption rate of up to 10350 (Pb(II)) and 14140 (Hg(II)) mg g(-1) h(-1) increased adsorbability order of Zn(II) < Fe(III) < Cu(II) << Ag(I) < Cd(II) < Pb(II) < Hg(II), and satisfactory removal of harmful heavy metal ions from ambient wastewaters, becoming ultrarapid chelate nanosorbents. Furthermore, PSA solution could be served as an advanced fluorescent chemosensor having ultrahigh sensitivity and high selectivity toward Pb(II) because of its very superior detection limit down to 1.0 x 10(-10) M and strong anti-interference to almost all other metal ions.