Ammonium persulfate

All chemicals used in this research were of analytical grade. Used granular black tea leaves were collected locally. Graphite powder used for the GO nanosheet synthesis was obtained from Sigma Aldrich (Saint-Louis, MO, USA). Ammonium persulfate, acetone, and ethanol were procured from Fisher Scientific, Loughborough, UK. Aniline was procured from Sisco Research Laboratories Pvt. Ltd. KBr (Sigma Aldrich) was used to prepare the bromide solution.

All chemicals were purchased from Sigma‐Aldrich unless otherwise specified and were used as received. 3‐(acrylamido)phenylboronic acid was purchased from Boron Molecular (catalog number BM1195). Glucagon, D‐glucose, tetramethylethylenediamine, bis‐acrylamide, and ammonium persulfate were purchased from Fisher Scientific (catalog number 50‐751‐6116, D16‐3, PI17919, BP171‐25, AC401160100).

Ammonium persulfate (APS, >98%), potassium persulfate (KPS, >99%), N,N’-methylenebis-acrylamide (BIS, 99%), nitric acid, hydrochloric acid (HCl), trisodium citrate dehydrate (99%), potassium carbonate (K₂CO₃, >99%), potassium hydroxide (KOH, 99.98%), phenylboronic acid (>98%), biphenyl (99%), absolute ethanol (EtOH), and hydrogen tetrachloroaurate trihydrate (HAuCl₄∙3H₂O, 99.995%) were obtained from Fisher Scientific. N-isopropylacrylamide (NIPAM, 99%, Aldrich) was recrystallized in hexanes and dried under vacuum prior to use. All glassware was cleaned with a strong acid solution and a base bath. The water used in all reactions was obtained from a Nanopure water system (Barnstead/Thermolyne).

Expansion of cultured U2Os cell was performed according to the protocol from M'Saad and Bewersdorf (2020) (link). In short, unstained U2Os cells were fixed with 4% paraformaldehyde for 15 min., washed with PBS and post-fixed with a 0.7% paraformaldehyde/1% Acrylamide solution. The fixed cells were embedded in a thin layer of gel (19% Sodium Acrylate, Chem Cruz, catalogue number sc236893; 10% Acrylamide, Sigma-Aldrich, catalogue number 1.19784.0100; 0.1% N,N′-Cystamine-bisAcrylamide, Sigma-Aldrich catalogue number 294381; 0.25% Ammonium persulfate, Fisher BioReagents, catalogue number 87687; and 0.25% N,N,N,N′-tetramethylethylenediamine, Sigma-Aldrich, catalogue number A4929).
The gel was allowed to polymerize for 1 h at 37°C. The cells in the gel were denatured in 1 ml denaturation buffer (200 mM SDS, 200 mM Sodium Chloride, 50 mM Tris-HCl pH 6.8) at 73°C for 1 h. After denaturation, all proteins in the gel were stained with 20 μg/ml NHS-ATTO594 (Sigma-Aldrich, catalogue number 08741) in 100 mM bicarbonate for 1.5 h. The gel was expanded in milli-Q water overnight. Afterwards the Gel was expanded in milli-Q water overnight. The resulting cells were expanded approximately seven times.