Liangyun Yu,Liangju Sun,Qi Zhang,Jingjing Zhang,Bairen Yang,Mingquan Huang,Yawen Zhou,Baocai Xu,Xiaoya Hu
This study developed an electrochemical sensor for the determination of Mn2+ in Chinese liquor by modifying a glass carbon electrode with TiO2-NH2@COFDPTB, which was synthesized via the controllable growth of COFDPTB onto the surface of TiO2-NH2 using the Schiff-base condensation reaction between 2,5-dimethoxyterephthalaldehyde and 1,3,5-tris(4-aminophenyl)benzene. The morphological and structural characterization studies of the proposed TiO2-NH2@COFDPTB were carried out by SEM, TEM, HRTEM, EDX, BET, XRD and FTIR techniques. Owing to the excellent properties and the synergism between TiO2 and COFDPTB, the introduction of TiO2-NH2@COFDPTB improved the electrochemical response significantly. By optimizing the experimental parameters, the sensor exhibited good linearity in the range of 0.1–1.0 nM and 0.08–10 μM with a detection limit of 2.83 × 10−11 M and 9.50 × 10−9 M, respectively, showing competitive performance for Mn2+ determination. Besides, the proposed sensor was successfully applied to Mn2+ detection in liquor samples, suggesting its practical application performance.
This paper presents a straightforward synthesis strategy for N, S co-doped carbon nanodots (N, S-CDs), aiming to achieve CDs emitting ultra-wide redshifts while obtaining excellent metal ion detection performance. The N, S-CDs display excellent fluorescence (FL) emission independence regardless of the excitation wavelength or concentration. By introducing a single dopant thiourea, the FL emission of CDs was red-shifted from 445 to 575 nm (∼130 nm). The doped N and S elements are discovered to cause the introduction of defective energy levels and an elevation in oxidation on the surface of CDs, which could potentially be the crucial factor for the ultra-wide redshift of FL emission. Also, it is investigated that solvent engineering is essential for the redshift of the emission peak, which can also be an effective way to synthesize multicolor CDs. Furthermore, the N, S-CDs can be utilized for measuring the water content in methanol solvent based on their solvent effects. Additionally, N, S-CDs have the capability of detecting Mn 2+ with high selectivity and sensitivity. The interaction of CDs with Mn 2+ resulted in an obvious change in both the UV absorption spectrum and FL lifetime. To put it differently, the reaction mechanism between CDs and Mn 2+ probably includes mixed processes of dynamic and static quenching. Zeta potential tests additionally indicate that the FL quenching is strongly correlated with the surface condition of CDs. The outcomes and discoveries offer a fresh and viable method for achieving the simultaneous production of long-wavelength glowing CDs and their analysis and detection of metal ions as fluorescent probes.
危险品化学品经营许可证（带存储）