Spectroscopic and potentiometric studies of the interaction of adenine with trivalent metal ions

Topological-Distortion-Driven Amorphous Spherical Metal-Organic Frameworks for High-Quality Single-Mode Microlasers

Metal-organic frameworks (MOFs) have recently emerged as appealing platforms to construct microlasers owing to their compelling characters combining the excellent stability of inorganic materials and processable characters of organic materials. However, MOF microstructures developed thus far are generally composed of multiple edge boundaries due to their crystalline nature, which consequently raises significant scattering losses that are detrimental to lasing performance. In this work, we propose a strategy to overcome the above drawback by designing spherically shaped MOFs microcavities. Such spherical MOF microstructures are constructed by amorphizing MOFs with a topological distortion network through introducing flexible building blocks into the growth environment. With an ultra-smooth surface and excellent circular boundaries, the acquired spherical microcavities possess a Q factor as high as ≈10⁴ and can provide sufficient feedback for high-quality single-mode lasing oscillations. We hope that these results will pave an avenue for the construction of new types of flexible MOF-based photonic components.

Probing the Interaction at the Nano-Bio Interface Using Raman Spectroscopy: ZnO Nanoparticles and Adenosine Triphosphate Biomolecules

With the advent of nanobiotechnology, there will be an increase in the interaction between engineered nanomaterials and biomolecules. Nanoconjugates with cells, organelles, and intracellular structures containing DNA, RNA, and proteins establish sequences of nano-bio boundaries that depend on several intricate complex biophysicochemical reactions. Given the complexity of these interactions, and their import in governing life at the molecular level, it is extremely important to begin to understand such nanoparticle-biomaterial association. Here we report a unique method of probing the kinematics between an energy biomolecule, adenosine triphosphate (ATP), and hydrothermally synthesized ZnO nanostructures using micro Raman spectroscopy, X-ray diffraction, and electron microscopy experiments. For the first time we have shown by Raman spectroscopy analysis that the ZnO nanostructures interact strongly with the nitrogen (N₇) atom in the adenine ring of the ATP biomolecule. Raman spectroscopy also confirms the importance of nucleotide base NH₂ group hydrogen bonding with water molecules and phosphate group ionization and their pH dependence. Calculation of molecular bond force constants from Raman spectroscopy reinforces our experimental data. These data present convincing evidence of pH-dependent interactions between ATP and zinc oxide nanomaterials. Significantly, Raman spectroscopy is able to probe such difficult to study and subtle nano-bio interactions and may be applied to elegantly elucidate the nano-bio interface more generally.