Anhydrous erbium chloride

Trisilanolisobutyl-POSS (Hybrid Plastic,
USA), tetramethylammonium hydroxide (25% in mEthanol, Alfa Aesar),
and (3-aminopropyl)triethoxysilane (98%, Alfa Aesar) were purchased.
Salicylaldehyde (98%), anhydrous erbium chloride (99.9%), anhydrous
terbium chloride (99.9%), and anhydrous samarium chloride (99.9%)
were purchased from Sigma-Aldrich (Darmstadt, Germany) and used without
further purification. Ethanol (HPLC grade, J. T. Baker, Gdańsk,
Poland), mEthanol (HPLC grade, J. T. Baker, Gdańsk, Poland),
acetonitrile (HPLC grade, J. T. Baker, Gdańsk, Poland), toluene
(HPLC grade, J. T. Baker, Gdańsk, Poland), and tetrahydrofuran
(Chempur) were purchased. All solvents, except mEthanol and acetonitrile,
were used with further purification. Tetrahydrofuran and toluene were
purified by distillation with sodium wires, and Ethanol was purified
with metallic magnesium.

Anhydrous yttrium trichloride (YCl₃, 99.99%), anhydrous ytterbium trichloride (YbCl₃, 99.9%), anhydrous erbium chloride (ErCl₃, 99.99%), 1-octadecene (ODE, 90%), oleic acid (OA, 90%), sodium hydroxide (NaOH, 96%), and ammonium fluoride (NH₄F, 96%) were purchased from Sigma-Aldrich. Trihydroxy methyl aminomethane (Tris), HCl, NaCl, KCl, CaCl₂, MgCl₂, CuCl₂, ZnCl₂, and FeCl₃ were obtained from Sinopharm. All chemicals were used directly without any further purification. Deionized water was purified by a Milli-Q system (Millipore, Bedford, MA, USA). The lead standard solution (1,000 mg/L) was purchased from Aladdin Industrial Inc. All nucleic acid molecules were prepared by Bioengineering Co., Ltd. (Shanghai). The sequences were as follows:
DNA1: 5′>AAGGGT GGGT GGGT <3′
DNA2: 5′>AAAAA AAAAA AAAAA AAAAA TTTTT CACCC TCCC AC <3′