Pb no3 2

Deoxyribonucleic acid (DNA) from salmon milt (ca. 100–300 bp, purity >90%) was purchased from Fujifilm Wako (Osaka, Japan). RNA from yeast was purchased from Tokyo Chemical Industry Inc. (Tokyo, Japan). Cytidine-5′-monophosphate (purity 98%), adenosine-5′-monophasphate (purity 98%), guanosine-5′-monophasphate (purity 97%), and uridine-5′-monophasphate (purity 98%) were purchased from Combi Blocks Inc. (San Diego, CA, USA). KNO₃, NaCl, CaCl₂·2H₂O, Al(NO₃)₃·9H₂O, Zn(NO₃)₂·6H₂O, Co(NO₃)₂·6H₂O, Pb(NO₃)₂, NiCl₂·6H₂O, Cu(NO₃)₂·3H₂O from Fujifilm Wako (Osaka, Japan), Hg(NO₃)₂·H₂O and AgNO₃ from Sigma-Aldrich (St. Louis, MO, USA), Cd(NO₃)₂·9H₂O from Combi-Blocks (San Diego, CA, USA), and MgCl₂·6H₂O from Kishida Chemicals (Osaka, Japan) were used for metal ion sensing experiments, as received. Unless otherwise mentioned, deionized water of resistivity 18.2 MOhm⋅cm and purified using a Purelab Chorus 1 Life Science apparatus was used in all experiments.

DNA sodium salt (>5 kbp, ca. 90% purity), CS (50 kDa–190 kDa, 75–85% deacetylation), and D-(+)-glucono-δ-lactone (GDL) were purchased from Sigma-Aldrich (St. Louis, MI, USA). Sodium hydroxide (NaOH), 6 M solution of hydrochloric acid, and sodium chloride (NaCl) were used as received. Congo Red from Kishida Chemical Co., Ltd. (Osaka, Japan) and 1% Methylene Blue solution (MB) form Kanto Chemical Co., Inc. (Tokyo, Japan) were used for dye adsorption experiments. Carbamazepine, ibuprofen, and ketoprofen were purchased from Wako Pure Chemical Industries, Ltd. (Osaka, Japan); clofibric acid, paracetamol, thymol, and 3,3’-Dihydroxydiphenylamine were purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan); and phenazone was purchased from Sigma-Aldrich (Japan). Standard solutions of 100 ppm (JCSS) of Cd(NO₃)₂, Cu(NO₃)₂, HgCl₂, and Pb(NO₃)₂ in 0.1 M HNO₃ were purchased from FUJIFILM Wako Pure Chemical Corporation (Osaka, Japan). Milli-Q water was purified by Purelab Chorus 1 Life Science apparatus and used in all experiments.