L ascorbic acid

Hydrogen tetrachloroaurate trihydrate (HAuCl₄·3H₂O), hexadecyl trimethyl ammonium bromide (CTAB, 99%), sodium borohydride (NaBH₄, 99%), doxorubicin (DOX) and tetraethyl orthosilicate (TEOS, 99%) were purchased from Sigma. Sodium oleate (NaOL, CP), silver nitrate (AgNO₃, AR), hydrochloric acid (HCl, AR), l-ascorbic acid (AA, 99.99%) were attained from Xilong scientific. Cyclohexane, dopamine hydrochloride (DA·HCl, 98%), H₂O₂ (AR, 30%), ammonia solution (NH₃·H₂O, 25–28%), 1,2-bis(triethoxysilyl)ethane (BTSE, 96%), tri(hydroxymethyl) amino methane hydrochloride (99%) and methanol were purchased from Aladdin Industrial Inc. Sodium hydroxide (NaOH, AR), acetone and nitric acid (AR, 65.0–68.0%) were purchased from Sinopharm Chemical Reagent. DMEM/HIGH glucose and penicillin–streptomycin solutions were purchased from HyClone. Phosphate buffered saline (PBS, 10×) was purchased from Solarbio. Fetal bovine serum (FBS) was purchased from Excell Bio. Cell Counting Kit-8 (CCK-8) and 4′,6-diamidino-2-phenylindole (DAPI) were purchased from Dojindo Laboratories (Japan). The ultrapure water with a resistivity of 18.2 MΩ cm was obtained from Milli-Q Gradient System (Millipore, Bedford, MA, USA) and used for all of the experiments.