Glycine

The SS was provided by Shougang Jingtang Iron and Steel United Co., Ltd. (Tangshan, China). Figure 1 displays the mineral compositions of the cement and SS, and Figure 2 depicts the particle size distribution of the SS and cement powder.
Glycine of 99% purity was purchased from Shanghai Macklin Biochemical Co., Ltd. (Shanghai, China). CO₂ gas with a purity of 99.9% was supplied by Beijing Hongmao Shuntong Energy Technology Co., Ltd. (Beijing, China).

Glycine, acrylamide solutions with 30% (w/v), SDS, ethylene diamine tetraacetic acid (EDTA), dithio-bis-nitrobenzoic acid (DTNB), 1-anilino-8-naphtha-lene sulfonate (ANS), Triton-X100, N,N,N′,N′-tetramethylethylenediamine (TEMED), and ammonium persulfate (APS) were provided by Macklin Biochemical Co., Ltd. (Shanghai, China). Ready-to-use protein molecular weight standard marker (6.5–200 kDa) was purchased from Sigma (St. Louis, MO). Disodium hydrogen phosphate (Na₂HPO₄), potassium dihydrogen phosphate (KH₂PO₄), potassium chloride, sodium hydroxide, ethanol, and other reagents were obtained from Hangzhou Jiecheng Biotechnology Co. (Hangzhou, China). All reagents were of analytical purity.
Giant squid, purchased from Zhoushan Second Ocean Fishery Co., Ltd. (Zhoushan, China), were immediately frozen without any treatment after being caught and stored at −20°C for less than 3 months. All squids were deheaded, degutted, and cleaned using water after they were defrosted in the air to room temperature. The mantles with the fins were sealed and stored at −40°C for further experiments.

Industrial graphene (reduced graphene oxide, rGO, >97%) and carboxylated carbon nanotube (CNT–COOH, >97%) were obtained from Timesnano (Chengdu, China). Co₃O₄ (99.5%, 30 nm) and Mn₃O₄ (97%) were obtained from Macklin Biochemical Co., Ltd. (Shanghai, China). PBSA (97%) was obtained from J&K (Shanghai, China) and PMS was obtained from Aladdin (Shanghai, China). Methanol and formic acid were of HPLC grade obtained from Sigma-Aldrich (Shanghai, China), and other reagents were of an analytical grade and they were obtained from Macklin Biochemical Co., Ltd. (Shanghai, China), including Co(NO₃)₂·6H₂O, Mn(NO₃)₂∙4H₂O, citric acid, glycine, humic acid (HA), absolute ethanol (EtOH), and tert-butanol (TBA).

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).

Tannic acid (TA), Cu(NO₃)₂·3H₂O, ethanol, hydrogen peroxide (30 wt%), 3,3′,5,5′-tetramethylbenzidine (TMB), L-proline, glycine, cysteine, alanine, glutamic acid, NaCl, KCl, MnCl₂·4H₂O, CaCl₂, glucose and L-glutathione reduced were purchased from Macklin Biochemical Co., Ltd. Ammonia solution (25–28 wt%) and formaldehyde (37–40 wt%) were purchased from Tianjin Zhiyuan Chemical Co., Ltd. Pluronic^® F127 was purchased from Sigma-Aldrich. The qualitative filter paper was purchased from Whatman. All the reagents were used without further purification. Deionized water from a Milli-Q Plus system (Millipore) was used in all experiments.