3 mercaptopropyl methyldimethoxysilane

All chemical reagents are analytical-graded reagents. Hydrogen tetrachloroaurate trihydrate (HAuCl₄), Phosphate buffered saline (PBS buffer), trisodium citrate solution (C₆H₅Na₃O₇, ≥99%), (3-Mercaptopropyl)methyldimethoxysilane (MPDMS, >95%), cystamine dihydrochloride (cystamine), dextran 70 (MW ≈ 70,000), sodium periodate (NaIO₄), 11-mercaptoundecanoic acid (MUA; ≥95%), 6-mercapto-1-hexanol (MCH; ≥97%), 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC), N-hydroxysulfosuccinimide (NHS), ethanolamine (EA), mouse IgG, streptavidin, monoclonal anti-HMGB1 antibody, and high mobility group box 1 (HMGB1) protein were from Sigma-Aldrich (St. Louis, MO, USA). Sulfuric acid (H₂SO₄; ≥98%), hydrogen peroxide (H₂O₂), ethanol, and acetate buffer were purchased from Fluka (Buchs, Switzerland). Ultrapure deionized water (18.2 MΩ·cm⁻¹, Milli-Q pure water purification system, Millipore Ltd., Burlington, MA, USA) was used for preparing solutions. The optical fiber probe was multimode plastic-clad silica optical fiber (model F-MBC, Newport), with core and cladding diameters of 400 and 430 μm, respectively, bought from Instant NanoBiosensors Co., Ltd. (Taipei, Taiwan). Sensing chips (poly (methyl methacrylate) (PMMA) plates) were prepared using a CO₂ laser engraving machine (New Taipei, Taiwan).

(3-mercaptopropyl)methyldimethoxysilane (MPDMS, ≥95%), 2,2’-dithiodipyridine, dichloromethane (anhydrous, 99.8%), petroleum ether, and isopropyl alcohol (IPA, 99.7%) were purchased from Sigma-Aldrich, St. Louis, MO, USA. SBR 1723 (styrene content: 23.5%, oil type: TDEA 37.5 phr, mooney viscosity (ML1 + 4): 49, coagulant: acid salt) was obtained from Kumho Petrochemical, Seoul, Korea. F-175 silica cake (pH: 7.0, loss on drying/105 °C × 2H: 6.0%, ignition loss at 1000 °C: 13.0%, oil absorption: 250 mL/100 g, Brunaeur–Emmett–Teller (BET): 175 m²/g) was purchased from Namhae Chemical, Yeosu, Korea. Bis[3-(triethoxysilyl)propyl] disulfide (TESPD (Si-75)) was purchased from Evonik Industries, Essen, Germany. Sodium hydroxide (NaOH, ≥96%) was obtained Samchun, Seoul, Korea. Various compounding processing additives such as zinc oxide (ZnO), stearic acid (S/A), and N-(1,3-dimethyl-butyl)-N’-phenyl-p-phenylenediamine (6PPD) were purchased from Sigma-Aldrich, USA. In the final compounding step, sulfur (Samchun, Seoul, Korea) was used as a crosslinking agent. N-cyclohexyl-2-benzothiazole sulfonamide (CBS) (Tokyo Chemical Industry, Tokyo, Japan) and diphenyl guanidine (DPG, Sigma-Aldrich, St. Louis, MO, USA) were used as crosslinking accelerators.