Concentrated hydrochloric acid

To ascertain the presence and abundance of various elements within the sample, ICP was utilized. Solid samples (e.g., 0.25 g–0.5 g) were weighed into a glass tube and 9 mL of concentrated hydrochloric acid (Sigma Aldrich, UK) added and 3 mL of concentrated nitric acid (Sigma Aldrich, UK) added. The samples were then placed into the heating block and the temperature was gradually raised to 150 °C and maintained at this temperature for 30 min. After removal from the block and cooling, the samples were diluted to 50 mL with 1% nitric acid. Samples were diluted down to 1 in 100 for analysis. Samples were analyzed using an ICP-OES (Spectro-Ciros-Vision Optical Emission Spectrometer (Spectro, Kleve, Germany) using a procedure with a detection limit of at least 10 ppm.

Analytical standards (purity > 98%) of 22BPF, BPAF, 24BPF, 44BPF, BPE, BPA, BPC, BPPH, BPP, BPBP, BPC2, BPZ, BPFL, BPAP and BPS were obtained from Sigma-Aldrich (St. Louis, USA), while BPB was purchased from Dr Ehrenstoffer (Augsburg, Germany). Isotopically labelled ¹³C₁₂-BPF, ¹³C₁₂-BPS, ¹³C₁₂-BPB (CanSyn Chem. Corp., Toronto, Canada) and deuterated BPA-d₁₆ (Sigma Aldrich, USA) were used as the internal standards. Acetone (>99.5%, AcO), acetonitrile (≥99.9%, MeCN), ethyl acetate (≥99.5%, EtAc) and methanol (≥99.8%, MeOH) were obtained from J. T. Baker (Deventer, the Netherlands). Concentrated hydrochloric acid (37%, HCl), formic acid (≥98%, FA) and ammonia (≥99.9%, NH₃) were purchased from Sigma Aldrich (St. Louis, USA). N-Methyl-N-(trimethylsilyl)trifluoroacetamide (>99.0%, MSTFA) and catalyst anhydrous pyridine (Pyridine, 99.8%) were obtained from Sigma Aldrich (Schnelldorf, Switzerland and Steinheim, Germany). Ultrapure water was prepared using the MilliQ-water purification system (Millipore Merck Direct-Q^TM) to a specific resistance of >18.0 MΩ cm^–1 at 25 °C. Individual compound stock solutions (≈ 1 mg L^–1) were prepared in MeOH, while standards and internal standards were prepared by serial dilution from the stock solutions.

Er(NO₃)₃·5H₂O (99.9%), Yb(NO₃)₃·5H₂O (99.9%), Y(NO₃)₃·6H₂O (99.9%), NaOH (analytical purity AR), absolute ethanol (AR), hydroxyethyl cellulose (AR, viscosity of 20,000 mPa s), polyethyleneimine (PEI, M.W. = 10000, 99%), NH4F (98%), concentrated hydrochloric acid (AR, 37%), dimethyl sulfoxide (DMSO, AR), 1-(3-dimethylamino propyl)-3-ethyl-carbodiimide hydrochloride (EDC, 98%), N-hydroxysuccinimide (NHS, 98%), phosphate-buffered saline (PBS, pH = 7.2–7.4), chlorin E6 (Ce6, 94%), and 1,3-diphenylisobenzofuran (DPBF, 99.9%) were procured through Sigma-Aldrich™ (St. Louis, USA). Anti-EpCAM monoclonal antibody was procured through eBioscience (San Diego, USA). A cellular proliferation kit (CCK-8) was procured through Abcam™ (Shanghai, China). 4′,6-Diamidino-2-phenylindole, dihydrochloride (DAPI) was procured through Sigma-Aldrich Chemicals™ (Sydney, Australia).
The human hepatocellular carcinoma cell line BEL-7404 was obtained from ATCC (Shanghai, China), and the LO₂ cell line was obtained from the Affiliated Hospital of Qingdao University, China. BEL-7404 cultures were grown within RPMI-1640 medium, and LO₂ cells were grown within DMEM augmented by 10% fetal bovine serum (FBS)/1% penicillin-streptomycin at 37°C within a humidified atmosphere carrying 5% CO₂.

The permanently charged precursor N-methyl-3-(trimethoxysilyl)-N,N-bis(3-(trimethoxysilyl)-propyl)propan-1-amonium iodide was synthesized following an adapted procedure with commercial reagents without solvents in standard and oven dried Schlenk flasks under argon. Concentrated hydrochloric acid (37%, Sigma-Aldrich, Saint Louis, MO, USA) and ammonia solution (30%, Sigma-Aldrich) were diluted in deionized (DI) water before use. Reticulated hydrogels were synthesized in DI water and absolute ethanol (>99.9% purity, VWR, Radnor, PA, USA) solvent mixtures and commercial reagents have been used without any further purification.

Squabs (28 days old, male, 250 g) were provided by Guangzhou Restaurant Co., Ltd, Guangzhou, China. Condiments, such as salt, spices, monosodium glutamate, and soy sauce, were purchased from Carrefour Supermarket (Haizhu District, Guangzhou). Sulfuric acid, boric acid, sodium hydroxide, ethanol, ketone sulfate, potassium sulfate, methyl red, bromocresol green, amino acid standard, concentrated hydrochloric acid, phenol, sodium citrate buffer solution, and ninhydrin solution were supplied by Sigma‐Aldrich (St. Louis, MO, USA).