N hydroxysuccinimide

Ferric chloride hexahydrate (FeCl₃·6H₂O), ethylene glycol (EG), diethylene glycol (DEG), Acid Phosphatase (AP, M_W = 10 kDa, EC 3.1.3.2), Superoxide Dismutase (SOD, ≥ 3000 U mg⁻¹, EC 1.15.1.1) and Chloroperoxidase (CPO, ≥ 3000 U mL⁻¹, EC 1.11.1.10) were purchased from Sigma-Aldrich. Sodium acetate (CH₃COONa, NaOAc), Poly (vinylpyrrolidone) (PVP, K30), Pyrogallol, Succinic anhydride and 3-aminopropyltriethoxysilane (APTES) was purchased from Aladdin. 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) were purchased from Energy Chemical, Fmoc-Tyr(H₂PO₃)-OH was purchased from GL Biochem. Tris·HCl buffer was purchased from Beijing Solarbio Science & Technology. Singlet Oxygen Sensor Green (SOSG) was purchased from Thermofisher. The aminophenyl fluorescein (APF) as the HClO detector were purchased from Shanghai Maokangbio. Enhanced BCA Protein Assay Kit was purchased from Beyotime Biotechnology. All materials were used without further purification.

Carboxyl PEG_2k‐N₃ and Methoxyl PEG_2k carboxyl were purchased from Ponsure Biological. Sodium ascorbate, Tri[(1‐benzyl‐1H‐1,2,3‐triazol‐4‐yl) methyl] amine (TBTA), and CuI were purchased from Accela ChemBio Co., Ltd. (Shanghai, China). N‐(3‐Dimethylaminopropyl)‐N’‐ethylcarbodiimide hydrochloride (EDC), 1‐Hydroxybenzotriazole (HOBt), N‐Hydroxysuccinimide (NHS), 4‐Dimethylaminopyridine (DMAP), and N,N‐Diisopropylethylamine (DIPEA) were purchased from Energy Chemical (Shanghai, China). PAMAM 5.0 was purchased from Weihai CY Dendrimer Technology Co., Ltd. (Shandong, China). 3‐Hydroxy‐4‐nitrobenzaldehyde was purchased from Shanghai Haohong Biomedical Technology Co., Ltd. (Shanghai, China). Propargyl bromide was purchased from Macklin Biochemical Co., Ltd. 4‐Nitrophenyl chloroformate and DPBF from Sigma–Aldrich. Antifade Mounting Medium with DAPI was purchased from Beyotime Biotech. Inc. (Shanghai, China). Resiquimod (R848) was purchased from Jiangsu Aikon (Jiangsu, China). Detailed information on the antibodies such as fluorescent antibody type, manufacturer, clone, and catalog number used in this study was provided in Tables S1–S3 (Supporting Information).

Methoxy-terminated polyethylene glycol (mPEG, Mw ≈ 2 KDa), carboxylic acid functionalized methoxyl polyethylene glycol (mPEG-COOH, Mw ≈ 2 KDa) were purchased from Ruixi Biological Technology Co., Ltd,. (Xi’an, China). N,N′-carbonyldiimidazole (CDI), 2,2-dithiodiethanol (DIT), succinic anhydride, dextran (Mw ≈ 2 KDa), 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC), N-Hydroxy succinimide (NHS), 2-methoxy propylene, pyridine p-toluene sulfonate, propionic anhydride, and dimethylaminopyridine (DMAP) were purchased from Energy Chemical (Shanghai, China). Water used in all the experiments was deionized (DI) water depurated by a Millipore ultrapure water system (Billerica, MA, United States) with a resistivity of 18.2 MΩ cm. High-glucose DMEM containing 1% penicillin/streptomycin, phosphate-buffered saline (PBS), and trypsin were obtained from KeyGen BioTech Co., Ltd,. (Jiangsu, China). Fetal bovine serum (FBS) was purchased from Absin Bioscience Inc (Shanghai, China).