Tris hydroxymethyl aminomethane tris

Polyethyleneimine (PEI), MW 15 000, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) were purchased from Sigma-Aldrich. Rose bengal (RB) was purchased from Aladdin Reagent Co., Ltd. Silver nitrate (AgNO₃) and glutaraldehyde (GA) were purchased from Alfa Aesar. Trisodium citrate (Na₃C₆H₅O₇·2H₂O) was purchased from Sinopharm Chemical Reagent Co., Ltd. Human immunoglobulin G (HIgG) and goat anti-human immunoglobulin (GaH-IgG) were purchased from Beijing Bioss Biotech Co., Ltd. Bovine serum albumin (BSA) were purchased from Nanjing KeyGEN Biotech. Co., Ltd. Polyoxyethylene (20) sorbitan monolaurate (Tween-20) and Tris (hydroxymethyl) aminomethane (TRIS) were purchased from Sinopharm Chemical Reagent Co., Ltd. The TBS buffer solution was prepared by dissolving NaCl (8.76 g) and TRIS (1.21 g) in water (500 mL). The TBS-T buffer solution was prepared by mixing Tween-20 (0.25 g) with TBS (500 mL). The BBS solution was prepared by dissolving sodium tetraborate in water to a concentration of 2 mM, reaching a pH of 9.0. P-doped, (100) oriented silicon wafers with a resistivity of 1–10 Ω cm were purchased from Suzhou Ruicai Semi-Conductor Co., Ltd. The water used in the experiments was ultrapure deionized water. All chemical reagents were used as received without further purification.

Human colorectal carcinoma cells SW620 were kindly gifted by Dr. Yong Cheng in the First Affiliated Hospital of Chongqing Medical University (Chongqing, China). Fetal kidneys cells HEK293T were generously provided by Dr. Songshan Jiang in Sun Yan-Sen University (Guangzhou, China). Human hepatocellular carcinoma cells HepG2 were kindly gifted by Dr. Hongshan Wei in Beijing Ditan Hospital Medical University (Beijing, China). Dulbecco's modified Eagle's medium (DMEM) medium, fetal bovine serum (FBS), bovine serium albumin (BSA) and MTT were purchased from Salarbio (Beijing, China). Dimethyl sulfoxide (DMSO) was purchased from Amresco (Solon, OH, U.S.). Chloroauric acid (HAuCl₄, 99%), silver nitrate (AgNO₃, ≥99.8%) and PDDA (MW = 100,000–200,000, 20 wt % in water) were purchased from Sigma-Aldrich. PSS (MW = 70,000) was purchased from J&K Scientific (Beijing, China). R6G dye was purchased from Aladdin (Shanghai, China). Sodium deoxycholate, Tween 20 and tris(hydroxymethyl)-aminomethane (Tris) were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China) and used without further purification. The 30 cm² polystyrene flasks and 96-well cell culture plates were purchased from Corning (New York, U.S.).