Nah2po4 2h2o

L-selenomethionine and L-methionine were obtained from Sigma-Aldrich (St. Louis, MO, USA). NaH₂PO₄·2H₂O, K₂HPO₄·3H₂O and methanol (analytical grade) were obtained from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). D₂O and 3-(Trimethylsilyl)propionic-2,2,3,3-d4 acid sodium salt (TSP-d4) were obtained from Cambridge Isotope Laboratories (Cambridge, MA, USA).

Steviol (99% of purity, HPLC) was purchased from Sigma-Aldrich Co., Ltd. (Shanghai, China). 5-Fluorouracil (5-FU), dimethyl sulfoxide (DMSO), Na₂CO₃, NaHCO₃, NaCl, KCl, Na₂HPO₄·12H₂O, NaH₂PO₄·2H₂O, EDTA disodium, dodecyl sodium sulfate (SDS), glycine, bromoxylenol blue, ammonium persulphate, tris (hydroxymethyl) methyl amino methane, ponceau, N,N,N, N-tetramethylethylenediamine (TEMED), xylene brilliant cyanin G (BS, G250), and phenylmethylsulfonyl fluoride (PMSF) were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Trypsin-EDTA solution, propidium iodide (PI), triton X-100, endonuclease (RNase A), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), penicillin-streptomycin solution (100X), bovine albumin (BSA), BeyoECL Plus, polyvinylidene fluoride, RIPA lysis buffer, and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyasix iodide (JC-1) were purchased from Beyotime Biotechnology Co., Ltd. (Shanghai, China). DMEM medium, fetal bovine serum were purchased from Gibco Life Technologies Corporation (Carlsbad, CA, USA). Primary antibodies against p21, p53, cyclin D1, Bax, Bcl-2, caspase 3, β-actin, and horseradish peroxidase (HRP)-conjugated secondary antibodies were purchased from Cell Signal Technologies Inc. (Beverly, MA, USA). All other reagents were of analytical grade and used as received unless otherwise stated.

Dulbecco’s modified Eagle’s medium (DMEM) and trypsin were purchased from Thermo Fisher Scientific Inc. (Beijing, China). Fetal bovine serum (FBS) was obtained from Hangzhou Sijiqing Company. Sodium penicillin and streptomycin were purchased from North China Pharmaceutical Company (Hebei, China). NaH₂PO₄ · 2H₂O, K₂HPO₄ · 3H₂O, K₂CO₃ and methanol (all in analytical grade) were purchased from Sinopharm Chemical Reagent Co. Ltd. (Shanghai, China). Deuterium oxide (D₂O, 99.9%D) and acetyl chloride were obtained from Sigma-Aldrich, Inc. (St. Louis, MO) and sodium 3-(trimethylsilyl) [2,2,3,3-²H₄] propionate (TSP) were obtained from Cambridge Isotope Laboratories, Inc. (Miami, U.S.A.). Phosphate buffer was prepared from NaH₂PO₄ and K₂HPO₄ with good low-temperature stability40 (link) containing 0.001% TSP (w/v) and 80% D₂O (0.15 M, pH 7.45) and employed as solvent for NMR analysis of tissue extracts.

Analytical-grade sodium chloride, DMSO, NaN₃, NaH₂PO₄•2H₂O, and Na₂HPO₄•12H₂O were purchased from Sinopharm Chemical Reagent Co. Ltd. (Shanghai, China). HPLC-grade CHCl₃ and CH₃OH were obtained from Merck (Darmstadt, Germany). D₂O (99.9% in D) containing sodium 3-(trimethyl-silyl) propionate-2, 2, 3, 3, d₄ (TSP) as an internal standard for chemical shift reference was provided by Sigma‒Aldrich (MO, USA). A buffer system containing 0.2 M Na₂HPO₄/NaH₂PO₄ in D₂O at pH 7.4 was prepared to prevent the pH effect on the chemical shifts of metabolites at different concentrations. The assay kits for the determination of sodium-potassium ATPase (Na-K-ATPase), cholinesterase (AChE) and lactate dehydrogenase (LDH) were purchased from Abcam (USA). The assay kits for dopamine (DA) were purchased from RD, USA, the assay kits for epinephrine (E) and norepinephrine (NE) were from Abnova, Taiwan, 5-hydroxytryptamine (5HT) assay kits were from BioSource, and gamma-aminobutyric acid (GABA) assay kits were from Santa Cruz, USA. The assay kits of superoxide dismutas (SOD), malonyldialdehyde (MDA), and glutathione peroxidase (GPx) were purchased from Cayman, USA.

Collagen (Col), myoglobin (Mb), glucoamylase (Glu), catalse (Cat) were from Aladdin Reagent Co. Ltd (Shanghai, China). Bovine serum albumin (BSA) was purchased from Gibco (Grand Island, USA). Lysozyme (Lys), pepsin (Pep), trypsin (Try), bovine albumin (BA), bovine hemoglobin (BHb), chloroauric acid tetrahydrate (HAuCl₄•4H₂O), NaOH, NaH₂PO₄·2H₂O, Na₂HPO₄·12H₂O, NaCl, KCl and CaCl₂ were obtained from Sinopharm Chemical Reagent Co., Ltd (Beijing, China). All chemicals were used as received without further purification. 96-well plates (Corning 3632) were obtained from Genetimes Technology. The stock solutions of proteins were prepared using 6 mM phosphate buffered saline (PBS, pH 7.4) buffer.
The pH measurements were performed using a PHS-3C pH meter. For all sensing experiments, imagings were acquired with a flatbed scanner (Epson Perfection V300) in 96-well plates. Transmission electron microscopy (TEM) was performed on a Tencai F20 instrument and operated at 200 kV. UV-vis absorption spectra were recorded using a Lambda 950 UV-vis spectrophotometer from Perkin Elmer. Zeta-potential of GNPs was measured using a Microtrac S3500 (Microtrac Inc., USA), and measured at 25 °C. FT-IR spectroscopy was performed using a Nicolet 6700 spectrometer.