Accurate detection of Cys/Hcy levels is critical for evaluating human health conditions. In this study, we developed an innovative fluorescence/colorimetric dual-mode sensing system to detect Cys/Hcy by dynamically adjusting the level of oxTMB. The system utilizes Au@PtNPs with peroxidase-like activity to catalyze the oxidation of colorless 3,3,5,5- tetramethylbenzidine (TMB) to blue oxTMB, and TAPB@DMTP COF, a fluorescent nanomaterial with abundant spatial pores, could be used as a carrier for oxTMB, and the two were made fluorescence quenching due to the fluorescence inner filter effect. The addition of Cys/Hcy allowed the originally dispersed Au@PtNPs to aggregate to inhibit their peroxidase-like activity, thus indirectly regulating the oxTMB content. At this point, the absorbance signal decreased and fluorescence was restored. To this end, we have developed a special fluorescence/colorimetric dual-mode sensing system for the detection of Cys/Hcy. The detection limits of the fluorescence and colorimetric methods for Cys/Hcy were determined to be 0.788 nM (Cys), 0.663 nM (Hcy), and 1.795 nM (Cys), 1.886 nM (Hcy), respectively. The sensing system was also evaluated for its ability to withstand interferences from 12 anions and 13 amino acids, demonstrating excellent unti-interference and selectivity. The recoveries of the two methods for detecting Cys/Hcy in fetal bovine serum were found to be 98.9%-114.3% with RSDs as low as 0.52% (fluorescence) and 0.92% (colorimetric), respectively.
Huacong Chu,Xin Sun,Xiaoqian Zha,Ya Zhang,Yang Wang
In this work, a novel core-shell structured CuO@TAPB-DMTP-COF composites were synthesized by encapsulating CuO nanorods into TAPB-DMTP-COF host matrix. The structural properties of the composites were revealed by X-ray diffraction pattern (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), and Transmission electron microscopy (TEM). Subsequently, the CuO@TAPB-DMTP-COF composites were immobilized on the glass carbon electrode (GCE) surface to fabricate an electrochemical sensor for dopamine detection. CuO functions as a highly catalytic active substance to accelerate the charge transfer rate of the reaction, while TAPB-DMTP-COF with a large electroactive surface area enhances the adsorption ability of the modified electrode toward the target molecules. The main parameters during the analytical procedure were investigated in detail, and the analytical performance was improved significantly due to the synergistic effects of CuO and TAPB-DMTP-COF. Under the optimal conditions, the dopamine peak responses are linear in a wide range from 0.07 to 800 μM, and the detection limit is as low as 0.023 μM. Furthermore, the dopamine sensor also exhibits good repeatability, stability, and accurate detection ability in actual samples. This study will expand the application of organic porous material based composites in ultra-sensitive electrochemical bioanalysis .
危险品化学品经营许可证（带存储）