Tetrabutyl titanate

The natural diatomite (denoted as D) used in this work is from Linjiang city, Jilin province, China [25 (link)]. The reagents used in this work are all purchased from Shanghai Macklin Biochemical Co., Ltd (Shanghai, China), including acetic acid (CH ${}_3$ COOH, AR), ethanol absolute (C ${}_2$ H ${}_5$ OH, AR), tetrabutyl titanate (C ${}_{16}$ H ${}_{36}$ O ${}_4$ Ti, donated as TBOT, AR), tert-butanol (C ${}_4$ H ${}_{10}$ O, donated as t-BuOH, AR), ethylenediaminetetraacetic acid disodium (C ${}_{10}$ H ${}_{14}$ N ${}_2$ Na ${}_2$ O ${}_8$ , donated as EDTA-2Na, AR), hydrochloric acid (HCl, AR), silver nitrate (AgNO ${}_3$ , AR) and zirconium oxychloride octahydrate (ZrOCl ${}_2$ ·8H ${}_2$ O, AR). Deionized water (≥10.0 M $\Omega$ cm) was used throughout our experiments.

Tetrabutyl titanate and 2-methylimidazole were purchased from Shanghai Macklin Biochemical Technology Co., Ltd. (Shanghai, China); N,N-dimethylformamide (DMF), anhydrous ethanol, polyethylene glycol 400 (PEG-400) and basic fuchsin were purchased from Tianjin Fuchen chemical reagent factory; europium nitrate hexahydrate was purchased from Tianjin Heowns Biochemical Technology Co., Ltd. (Tianjin, China); glacial acetic acid was purchased from Tianjin New Technology Industrial Park Kemao Chemical Reagent Co., Ltd. (Tianjin, China); and zinc nitrate hexahydrate was purchased from Chengdu Ai Keda Chemical Reagent Co., Ltd. (Chengdu, China)

Potassium iodide, 2-methylimidazole and tetrabutyl titanate were purchased from Macklin (Shanghai, China); N, N-dimethylformamide (DMF), anhydrous ethanol, polyethylene glycol 400 (PEG-400) and Congo red were purchased from Fuchen Chemical (Tianjin, China); glacial acetic acid was purchased from Kemao Chemical (Tianjin, China), and zinc nitrate hexahydrate was purchased from Aike Chemical (Chengdu, China).

All reagents were not purified further before use. Methylbenzene, hydrochloric acid (HCl), lysine (Lys), arginine (Arg), titanium tetrachloride (TiCl₄), tetrabutyltitanate, gold (III) chloride (HAuCl₄·3H₂O), leucine (Leu), cysteine (Cys), proline (Pro), glycine (Gly), barium hydroxide octahydrate (Ba(OH)₂·8H₂O), formic acid, ethylene diamine tetraacetic disodium (EDTA−2Na), chloroplatinic acid (H₂PtCl₆), 3,3′,5,5′−tetramethylbenzidine (TMB, ≥99%), L−histidine (L−His), glutathione (GSH), glutamic acid (Glu), and fetal bovine serum were purchased from Macklin Biochemical Co., Ltd. (Shanghai, China). Sodium borohydride (NaBH₄), disodium hydrogen phosphate (Na₂HPO₄), p−Benzoquinone (p−BQ), isopropanol (IPA), potassium nitrate (KNO₃), citric acid, ascorbic acid (AA), and sodium nitrate (NaNO₃) were purchased from Sinopharm Chemical Reagents Co., Ltd. (Shanghai, China).

Retinoic acid, Tetrabutyl titanate, and Rhodamine B (RB) were purchased from Shanghai MackLin Biochemical Co., Ltd; absolute ethanol (analytical grade), and glacial acetic acid (analytical grade), 98% concentrated sulfuric acid (analytical grade), 30% hydrogen peroxide (analytical grade) and chitosan were purchased from Sinopharm Chemical Reagent Co., Ltd; silica was purchased from XFNANO company; polyacrylic acid (PAA) and polyethyleneimine (bPEI) were purchased from Sigma-Aldrich; water was made in the laboratory.