AIEgens-based fluorescent covalent organic framework in construction of chemiluminescence resonance energy transfer system for serum uric acid detection

A covalent organic framework (COF) with aggregation-induced emission (AIE) property was successfully synthesized through in situ marriage of a commonly used AIE molecule tetraphenylethylene (TPE) with Schiff base network (SNW-1) through a simple one-pot method. The TPE@SNW-1 was characterized with different techniques of Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and nitrogen adsorption/desorption experiments. The fluorescence of the TPE@SNW-1 strongly depends on the composition of tetrahydrofuran–water binary system. The AIE property of TPE@SNW-1 was directly supported with particle size distribution by dynamic light scattering technique. With the TPE@SNW-1 as an energy acceptor, a chemiluminescence resonance energy transfer (CRET) system was constructed with bis(2,4,6-trichlorophenyl) oxalate (TCPO)–hydrogen peroxide (H₂O₂) reaction as an energy donor. The chemiluminescence (CL) signal displays a good linear relationship with concentration of H₂O₂ in the 5.0–1000.0 μmol·L⁻¹ range, and a detection limit of 2.34 μmol L⁻¹. The system was further exploited to determine uric acid based on the fact that equal stoichiometric amount of H₂O₂ can be concurrently generated under the catalysis of uricase. The procedure exhibits a linear response to uric acid concentration in the range 10.0–150.0 μmol·L⁻¹ and a detection limit of 4.94 μmol·L⁻¹. The practicability of the method was demonstrated in the determination of uric acid in human serum samples. Graphical abstract: [Figure not available: see fulltext.]