Chloroauric acid haucl4 4h2o

To evaluate the performance of FICT assay, colloidal gold nanoparticles conjugated to Ab was prepared as previously described^{50 (link)}. After 0.02% chloroauric acid (HAuCl4·4H₂O) (Sigma-Aldrich) was brought to a boil, 0.2% sodium citrate was added with constant stirring. After the mixture changed to a wine-reddish color, the solution was boiled for additional 5 min and then stirring for 10 min without boiling. Next, 1 mg of the mAb (2F4) was conjugated with the prepared colloidal gold particles (100 mL). The mAb-gold conjugate was precipitated by centrifugation (27,237 × g) and resuspended in PBS containing 0.1% of BSA to an optical density at 450 nm (OD₄₅₀) of 10. The TL of the strip was prepared by dispensing a desired volume of 2.5 mg/mL mouse mAb (6D7) and 0.5 mg/ml IgG mouse on the CL. Same lysis buffer was used for RDT. A commercial influenza virus A/B RDT (Standard Diagnostics, Yongin, South Korea) was used for comparison. Samples were applied following the manufacturer’s instructions.

Chloroauric acid (HAuCl₄·4H₂O) and sodium borohydride were purchased from Sigma-Aldrich. All chemical reagents were analytical grade and used without further processing. The hIAPP_20–29 (SNNFGAILSS) was synthesized and analyzed by Guoping Pharmaceutical Co., Ltd. (Hefei, China). Deionized water with a resistivity of 18.2 MΩ was used for all solution preparation.

All chemicals were used as received without further purification. Ferric chloride hexahydrate (FeCl₃.6H₂O), 5, 10, 15, 20-tetra (4-(imidazol-1-yl)phenyl) porphyrindine (TIPP), polyvinylpyrrolidone (PVP, Mw~4000) and tetraethyl orthosilicate (TEOS) were purchased from Aladdin Company. Ethanol (CH₃CH₂OH, 99.7%), N, N-dimethylformamide (DMF, AR), α,α‘-Dibromo-p-xylene, sodium sulfate anhydrous (Na₂SO₄), sodium hydroxide (NaOH), hydrogen chloride (HCl, 37%) were purchased from Sinopharm Chemical Reagent Co., Ltd. Chloroauric acid (HAuCl₄·4H₂O) was purchased from Sigma-Aldrich. Dopamine HCl was purchased from Beijing HWRK Chem Co., Ltd. 3,3’,5,5’-tetramethylbenzidine (TMB) and PBS were gotten from Sangon Biotech (Shanghai) Co., Ltd. Glucose, fructose, sucrose, L-cysteine, ascorbic acid, dopamine, uric acid, and maltose were purchased from Beijing Chemical Reagent Company. Deionized (DI) water from Milli-Q System (18.2 MΩ·cm, Millipore, Billerica, MA) was used in all experiments.