L fucose

Fucoidan standard extracted from U. pinnatifida (Fstd) was purchased from Sigma-Aldrich (Buchs, Switzerland). Sugar standards including _L-fucose, _D-galactose, and _D-glucose were purchased from Macklin (Shanghai, China). Synthetic antioxidants BHA, sodium hydroxide (≥99.0%), and ascorbic acid were also purchased from Macklin (Shanghai, China). Anhydrous ethanol (≥99.0%), hydrochloric acid (4 M), trifluoroacetic acid (≥99.0%), ferrous sulfate (9 mM), hydrogen peroxide (0.3%), ethanolic solution of salicylic acid (5 mM), potassium ferricyanide, 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-hydrazyl (DPPH) and dialysis bags were purchased from Solarbio (Beijing, China). All other chemicals used in this study were of analytical grade.

2,2′-(Ethylenedioxy)bis(ethylamine), dopamine hydrochloride and D-mannose were obtained from Xianding Biotechnology Co. (Shanghai, China). Methyl pentafluorobenzoate and aminoacetic acid was obtained from Shanghai Aladdin Bio-Chem Technology Co. (Shanghai, China). N-acetyl-d-glucosamine and l-fucose were obtained from Shanghai Macklin Biochemical Co. (Shanghai, China). Bovine serum albumin (BSA) and d-galactose were obtained from Energy Chemical (Shanghai, China). SBA, WGA, PNA, and UEA-I were obtained from Vector Laboratories (Burlingame, CA, USA). Con A, concanavalin A fluorescein conjugate (FITC-Con A) and tris(hydroxymethyl)amino-methane (Tris) were obtained from Sigma-Aldrich (Shanghai, China).
¹³C, ¹⁹F and ¹H NMR spectra were recorded by using a Bruker AVANCE III HD 500 MHz Spectrometer (Karlsruhe, Germany) in CDCl₃. SEM-EDX were obtained using the S-4800 instrument (Hitachi Ltd.) with an accelerating voltage of 10.0 kV. The photochemistry in this work was undertaken with a Rayonet PRP-100 photochemical reactor (Branford, CT, USA). The experiments were carried out using an Attana QCM Cell-A200 (Stockholm, Sweden) (Figure 1). An Attana gold sensor (Stockholm, Sweden) was used for further modifications to obtain a carbohydrate sensor.