β-Amino aldehydes, in addition to being biologically relevant, serve as potential entry points to γ-amino alcohols and β-amino acids. While formylation of alkenes has been explored in both conventional and photochemical realms, there are no dedicated reagents that can incorporate amine and aldehyde simultaneously. This work demonstrates the development and application of an oxime ester reagent derived from glyoxylic acid acetal that, under photosensitized energy transfer conditions, delivers iminyl and acetal fragments onto alkenes via a diradical mode, leading to β-amino aldehydes.
View Article and Find Full Text PDFThe advancement of multifunctional metal-organic frameworks (MOFs) incorporating task-specific sites holds significant potential for carbon footprint reduction. We report the synthesis of a thermochemically robust and microporous, charged Co(II)-organic framework, assembled from a -NH-functionalized dicarboxylate ligand, a triazine core containing a tris-pyridyl linker, and an in situ generated [Co(μ-O)(COO)N] secondary building unit. Interestingly, -symmetric linkers partition the larger channels into trigonal-bipyramidal-shaped smaller cages.
View Article and Find Full Text PDFA mixed-ligand-based novel 3D Cd(II)-based metal-organic framework (MOF) is devised from π-electron-rich organic struts that shows two-fold interpenetrated bilayer-pillar structure. The strong luminescence of the MOF gets remarkably quenched by roxarsone (ROX) organo-arsenic in water. The material further exemplifies one-of-a-kind fluoro-switchable probe for antibiotics and exhibits massive turn-off emission by tetracycline (TTC), whereas sulfamethazine (SMZ) triggers an unprecedented 120% emission enhancement.
View Article and Find Full Text PDFThe non-structural protein NS2B plays a critical role in the maturation of Dengue virus (DENV Type 2). The underlying mechanism and the role of NS2B are largely unknown due to the unavailability of its location of activity in the target organelle at single molecule level. This is largely due to the incapability of existing optical microscopes to resolve features beyond the diffraction limit of light ([Formula: see text]), which is limited to a few hundred nanometers.
View Article and Find Full Text PDFAlkyl radicals represent some of the most intriguing prospects in organic synthesis, showing diverse patterns of reactivity for versatile transformations. In light of this, the methyl radical, in addition to being a methylating agent, is also a good proposition for hydrogen atom transfer (HAT). Similarly, acetonitrile also has dual facets to its reactivity, acting as an amination reagent in the Ritter reaction while also being the progenitor to cyanomethyl radicals through HAT.
View Article and Find Full Text PDFAminophosphonates serve as extremely important moieties with respect to their activities in biological systems. However, incorporating a Nitrogen and Phosphorus moiety by conventional techniques in ionic mode is usually associated with extensive prefunctionalization of the substrates, employing harsh conditions and reagents that limit the viability of these methods. Introducing both of these components as radicals may be a viable option.
View Article and Find Full Text PDFA mixed-ligand-based thermo-chemically robust and undulated metal-organic framework (MOF) is developed that embraces carboxamide moiety-grafted porous channels and activation-induced generation of open-metal site (OMS). The guest-free MOF acts as an outstanding heterogeneous catalyst in Hantzsch condensation for electronically assorted substrates with low catalyst loading and short duration under greener conditions than the reported materials. Besides Lewis acidic OMS, the carboxamide group activates the substrate via two-point hydrogen bonding, highlighting the effectiveness of custom-made functionalities in this multi-component reaction.
View Article and Find Full Text PDFSingle-molecule localization microscopy (SMLM) can decipher fine details that are otherwise impossible using diffraction-limited microscopy. Often, the reconstructed super-resolved images suffer from noise, strong background and are prone to false detections that may impact quantitative imaging. To overcome these limitations, we propose a technique (corrSMLM) that recognizes and detects fortunate molecules (molecules with long blinking cycles) from the recorded data.
View Article and Find Full Text PDFTo be able to resolve multiple organelles at high throughput is an incredible achievement. This will have immediate implications in a range of fields ranging from fundamental cell biology to translational medicine. To realize such a high-throughput multicolor interrogation modality, we have developed a light-sheet based flow imaging system that is capable of visualizing multiple sub-cellular components with organelle-level resolution.
View Article and Find Full Text PDFDevelopment of high-performing catalytic materials for selective and mild chemical transformations through adhering to the principles of sustainability remains a central focus in modern chemistry. Herein, we report the template-free assembly of a thermochemically robust covalent organic polymer (COP: ) from 2,2'-bipyridine-5,5'-dicarbonyl dichloride and 2,4,6-tris(4-aminophenyl)triazine as [2 + 3] structural motifs. The two-dimensional (2D) layered architecture contains carboxamide functionality, delocalized π-cloud, and free pyridyl-N site-decked pores.
View Article and Find Full Text PDFStimuli-responsive emission color modulation in fluorescent metal-organic frameworks (MOFs) promises luminescence-ink-based security application, while task-specific functionality-engineered pores can aid fast-responsive, discriminative, and ultralow detection of harmful organo-aromatics in the aqueous phase. Considering practical applicability, a self-calibrated fluoro-switch between encrypted and decrypted states is best suited for antiforgery measures, whereas image-based monitoring of organo-toxins by repetitive and handy methods over multiple platforms endorses in-field sensory potential. Herein, we constructed a mixed-ligand based chemically stable and bilayered-pillar MOF from -NH-hooked pyridyl linker and tricarboxylate ligand that embraces negatively charged [Cd(μ-OH)(COO)] node and shows pore-space-partitioning by nitrogen-rich flanked organic struts.
View Article and Find Full Text PDFOver the last decade, single-molecule localization microscopy (SMLM) has developed into a set of powerful techniques that have improved spatial resolution over diffraction-limited microscopy and demonstrated the ability to resolve biological features down to a few tens of nanometers. We introduce a single molecule-based scanning SMLM (scanSMLM) system that enables rapid volume imaging. Along with epi-illumination, the system employs a scanning-based 4f detection for volume imaging.
View Article and Find Full Text PDFHerein, we disclose a simple strategy for the C-H alkylation of electron-rich (hetero)arenes with alkyl bromides employing visible-light-mediated organo-photocatalytic SET processes. The generality of this method has been evidenced by the inclusion of a variety of alkyl radicals (α-alkyl-carbonyl, benzyl, cyanomethyl) as well as diverse biologically active electron-rich arenes and (hetero)arenes under mild conditions. The extent of alkylation with alkyl bromides was found to be controlled by introducing Zn(OAc) as a bromide scavenger, ensuring the blocking of potential bromo-arene byproduct formation under photoredox conditions.
View Article and Find Full Text PDFThe blinking properties of a single molecule are critical for single-molecule localization microscopy (SMLM). Typically, SMLM techniques involve recording several frames of diffraction-limited bright spots of single-molecules with a detector exposure time close to the blinking period. This sets a limit on the temporal resolution of SMLM to a few tens of milliseconds.
View Article and Find Full Text PDFConcerning environmentally benign catalysis with reduced chemical usage, less energy consumption, and waste minimization, metal-organic frameworks (MOFs) with spatially isolated task-specific functionalities not only execute atom-economic important reactions but also enable size-exclusive catalysis at the interface of structure-function synergy. Herein, we synthesized a bipillar-layer Co(II) MOF from the dicarboxylate ligand and carboxamide moiety grafted pyridyl linker. The framework contains a [Co(COO)N] secondary building unit (SBU) and shows excellent hydrolytic stability due to ample non-covalent interactions among the highly conjugated aromatic struts.
View Article and Find Full Text PDFDevelopment of the multifaceted metal-organic framework (MOF) with in situ engineered task-specific sites can promise proficient oxygen evolution reaction (OER) and high-temperature adsorption cum mild-condition fixation of CO. In fact, effective assimilation of these attributes onto a single material with advance performance characteristics is practically imperative in view of renewable energy application and carbon-footprint reduction. Herein, we developed a three-fold interpenetrated robust Co(II) framework that embraces both redox-active and hydrogen-bond donor moieties inside the microporous channel.
View Article and Find Full Text PDFBioresour Technol
February 2023
Machine Learning is quickly becoming an impending game changer for transforming big data thrust from the bioprocessing industry into actionable output. However, the complex data set from bioprocess, lagging cyber-integrated sensor system, and issues with storage scalability limit machine learning real-time application. Hence, it is imperative to know the state of technology to address prevailing issues.
View Article and Find Full Text PDFMolecules capable of emitting a large number of photons (also known as fortunate molecules) are crucial for achieving a resolution close to single molecule limit (the actual size of a single molecule). We propose a long-exposure single molecule localization microscopy (leSMLM) technique that enables detection of fortunate molecules, which is based on the fact that detecting a relatively small subset of molecules with large photon emission increases its localization precision (∼r/N). Fortunate molecules have the ability to emit a large burst of photons over a prolonged time (> average blinking lifetime).
View Article and Find Full Text PDFOptical trapping and patterning cells or microscopic particles is fascinating. We developed a light sheet-based optical tweezer to trap dielectric particles and live HeLa cells. The technique requires the generation of a tightly focussed diffraction-limited light-sheet realized by a combination of cylindrical lens and high NA objective lens.
View Article and Find Full Text PDFOptical imaging is paramount for disease diagnosis and to access its progression over time. The proposed optical flow imaging (VFC/iLIFE) is a powerful technique that adds new capabilities (3D volume visualization, organelle-level resolution, and multi-organelle screening) to the existing system. Unlike state-of-the-art point-illumination-based biomedical imaging techniques, the sheet-based VFC technique is capable of single-shot sectional visualization, high throughput interrogation, real-time parameter estimation, and instant volume reconstruction with organelle-level resolution of live specimens.
View Article and Find Full Text PDFContinuous monitoring of large specimens for long durations requires fast volume imaging. This is essential for understanding the processes occurring during the developmental stages of multicellular organisms. One of the key obstacles of fluorescence based prolonged monitoring and data collection is photobleaching.
View Article and Find Full Text PDFTo be able to resolve molecular-clusters it is crucial to access vital information (such as, molecule density, cluster-size, and others) that are key in understanding disease progression and the underlying mechanism. Traditional single-molecule localization microscopy (SMLM) techniques use molecules of variable sizes (as determined by its localization precision (LP)) to reconstruct a super-resolution map. This results in an image with overlapping and superimposing PSFs (due to a wide size-spectrum of single-molecules) that undermine image resolution.
View Article and Find Full Text PDFBackground: Cholera is a primordial disease caused by which existed from centuries in different parts of the world and still shows its periodic, endemic and epidemic presence. Thousands of cholera cases are reported from different parts of India and the disease remains endemic throughout the year. At present, we do not have enough knowledge about the phenotypic nature of the circulating strains in this part of the world.
View Article and Find Full Text PDFWe propose and demonstrate a modified spatial filter-based single-shot lithography technique for fabricating an array of microfluidic channels. This is achieved by illuminating the photopolymer specimen with a multiple light sheet (MLS) pattern. Modified spatial filtering is employed in a cylindrical lens system to generate the MLS pattern.
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