Graphical We demonstrate the temporal programming of the assembly and disassembly of EuW 10 nanospheres using a pH clock reaction of acid/urease hydrolysis. The pH-responsive C 12 DMAO endow EuW 10 nanospheres with dynamical properties, in which fluorescence changes are coded in this system. These fluorescent nanospheres provide new application in time-programmed information encryption. Self-assembly exploits noncovalent interaction to offer an effective method for the fabrication of materials. For Na 9 [EuW 10 O 36 ] ⋅ 32H 2 O (EuW 10 ), the negative charges and abundant oxygen atoms on its surface provide a handle for static self-assembly. New properties are envisioned for EuW 10 aggregates which are able to display such kinetics and time-programming characteristics, in order to satisfy more complex and intelligent application scenarios, such as DNA binding and information encryption. In this work, EuW 10 coupling with stimuli-responsive dodecyl dimethylamine oxide (C 12 DMAO) can generate versatile aggregates with pH-responsive properties. We demonstrated the temporal programming of the assembly and disassembly of EuW 10 nanospheres using a pH clock reaction of acid/urease hydrolysis. The pH clock reaction endows EuW 10 assemblies with dynamical properties, in which the charges and fluorescence changes are coded in this system. These fluorescent assemblies provide new application in time-programmed DNA capture and information encryption.
Yi Wang,Cuiyan Wu,Jie Chen,Zhiyou Miao,Qiang Wang,Lijuan Luo,Zhongyong Zhang,Minjie Hu,Zhijian Jia
Although chemical kinetics is an essential branch of physical chemistry, observing kinetic processes typically demands sophisticated and costly equipment. Digital green chemistry experiments are an important experimental-teaching direction for undergraduates. This study introduces a portable, interactive, and educational microarray chip platform that visualizes chemical kinetics through clock reactions via dynamic mixing. The microfluidic chip consists of a 3D-printed substrate, modeled in Cinema 4D, and an acrylic glass cover. By precisely controlling variables such as the reactant concentration and temperature with digital coding, we successfully demonstrate two iodine clock reactions, KIO3-KI-H+ and Na2S2O3-I2-(NH4)2S2O8, as well as anthocyanin discoloration. This platform enables the clear visualization of phenomena including radial diffusion and microscale interfacial reactions, presenting the reaction progress in a color-card format referred to as “chemical amber,” which enhances the understanding of abstract chemical concepts. Notably, the chip allows users to calculate key kinetic parameters, including reaction rates, activation energy, and analyte concentration, by measuring diffusion rates, color-change times, and grayscale values from digitally scanned images obtained using a low-cost mini USB-electronic microscope and smartphone. This provides an enriched understanding of reaction dynamics. Furthermore, the platform was successfully implemented in comprehensive experimental teaching applications, demonstrating notable effectiveness in classroom settings.
Chiral enantiomers of drugs often exhibit distinct pharmacological activities despite their similar physical and chemical properties. Developing efficient methods for their distinguishment is crucial for pharmaceutical quality control. Here, we presented a novel approach using a CTT (Chlorite-Tetramethylammonium Hydroxide-Tetrathionate) clock reaction system for kinetic chiral enantiomer recognition. DOPA enantiomers were selected for this purpose, in which L-DOPA is therapeutic efficacy in treating Parkinson's disease by precursoring dopamine while D-DOPA lacks such a function. By introducing equal amounts of L-DOPA and D-DOPA into the CTT clock system, we observed a more prolonged induction period for L-DOPA compared to D-DOPA, enabling their quick differentiation. Moreover, a linear relationship between the induction period and the concentration (1.190 × 10 −6 mol/L to 4.5238 × 10 −6 mol/L) of L-DOPA or D-DOPA allowed quantitative detection of L-DOPA or D-DOPA samples. This method could also be applied to analyze varying concentration ratios of L-DOPA and D-DOPA mixtures at a fixed total concentration. Study on mechanism indicates that both L-DOPA and D-DOPA react with ClO 2 · radical to finally generate DHICA through oxidation, with their kinetic disparities evident during this process. These kinetic disparities between L-DOPA and D-DOPA oxidation arises from stereospecific hydrogen-bonding interactions in the cyclodopa intermediate. The weaker hydrogen bond in L-DOPA-derived cyclodopa likely facilitates its cleavage during oxidation, thereby accounting for the faster reaction kinetics observed in the clock system compared to D-DOPA. This makes L-DOPA exhibit more fast consumption of chlorine dioxide than D-DOPA, and resulting larger the extension in the induction period with L-DOPA than that with D-DOPA. Such a method coupling CCT clock demonstrates its versatility and potential for broader applications in chiral drug analysis.
危险品化学品经营许可证（带存储）