Although inherently chiral selectors are successfully used as modified solid electrodes, homogeneously doped chiral ionic liquids for analytical sensing remain largely unexplored. Herein, we present inherently chiral mono and disubstituted alkyltetrathia[7]helicene derivatives as uncharged additives dissolved in the achiral commercial ionic liquid 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM][TFSI]). Unlike unsubstituted thiahelicenes that undergo oxidative electrooligomerization to form solid films, adding aliphatic chains improves monomer solubility and sterically prevents film formation. The capacity of these molecules to induce a pervasive chiral environment was macroscopically validated by a high helical twisting power in nematic liquid crystals. At the electrochemical interface, enantiopure (+)‐( P )‐ and (−)‐( M )‐7,8‐dipropyltetrathia[7]helicenes acted as soluble chiral inductors. Voltammetry using ( R )‐ and ( S )‐ N , N ‐dimethyl‐1‐ferrocenylethylamine probes demonstrated unprecedented enantiodiscrimination, yielding a substantial thermodynamic peak potential separation (Δ E > 200 mV). Preliminary validation with the individual enantiomers of the pharmaceutical drug lansoprazole provided initial evidence of thermodynamic recognition beyond standard model probes. Differential pulse voltammetry on disposable screen‐printed electrodes allowed precise enantiomeric excess evaluation with strict linear correlation ( R 2 > 0.992), high sensitivity, and high reproducibility (RSD < 3.8%). This homogeneous setup overcomes the historical fouling of solid electrodes, providing a robust, time‐efficient, and fouling‐free platform for solution‐phase chiral analysis.
Covalent organic frameworks (COFs) represent a class of crystalline porous materials composed of lightweight organic small molecules interconnected by robust covalent bonds. These materials are characterized by highly ordered pore structures, as well as tunable chemical compositions and functions. This article presents a systematic review of the recent advancements in COFs for sample pretreatment over the past 5 years. It summarizes the applications of these COFs in solid‐phase extraction, dispersive solid‐phase extraction, magnetic solid‐phase extraction, and microextraction techniques, focusing on functionalization design and application. This review demonstrates that through appropriate structural modification and composite design, COFs can efficiently and selectively enrich trace targets in complex samples while exhibiting excellent extraction capacity and reusability. Moreover, these COFs showed excellent potential to remove interferents from complex samples for improving the selectivity of analytical approach. Finally, this review offers a perspective on the future development of COF‐based sample pretreatment strategies.
Aptamers that undergo structural rearrangement upon ligand binding have increasingly been translated into sensing platforms such as electrochemical aptamer‐based biosensors. However, successful conversion from SELEX‐derived binders to functional sensors frequently requires extensive post‐SELEX engineering, which is typically performed in a largely empirical manner using nuclease digestion, truncation strategies, or computational predictions. Critically, these approaches do not explicitly account for ligand‐induced conformational change, a property widely proposed to be central to signal generation in structure‐switching aptamer sensors. To address this limitation, we evaluated whether solution‐based biophysical techniques—specifically isothermal titration calorimetry and NMR spectroscopy—could provide rational guidance for post‐SELEX engineering by directly reporting on global structural responses to ligand binding. This effort was enabled by the development of a new quantitative framework that, for the first time, allows the magnitude of ligand‐induced conformational change in aptamers to be experimentally measured. Using these methods, we established quantitative descriptors of aptamer structural remodeling and correlated them with downstream sensor performance. In doing so, we found that, while binding and ligand‐induced folding are necessary, sequence length emerges as the strongest predictor of successful sensor translation, likely reflecting its central role in mediating signal transduction.
Although originally used to study development, zebrafish ( Danio rerio ) have emerged as a model used to investigate neuronal function in health and disease. Zebrafish are advantageous for this purpose because they are easy to genetically manipulate, are economical to maintain, and share many evolutionarily conserved similarities with the mammalian central nervous systems. Importantly, ex vivo and in vivo preparations are amenable to analytical measurements that employ electrochemical and optical methods to measure fluctuations in neurotransmitter levels. In this review, we take a deeper look into how the inherent advantages of this model organism have been leveraged to unravel fundamental processes involved in neuronal function. To provide proper background and context, we first describe details on how zebrafish became a model for the study of development. We then provide an overview of zebrafish neuroanatomy, highlighting comparisons to mammals. Next, we discuss analytical methods that have been used to measure neurotransmitter and neuromodulatory levels in zebrafish. Finally, we examine specific applications of these methods used to measure real‐time changes in neurochemical levels. This review focuses on electrochemical and fluorescent sensing approaches for monitoring neurochemicals in viable zebrafish preparations, rather than providing a comprehensive examination of extracted‐tissue assays or clinical molecular imaging methods.
Protein adsorption on solid materials plays a central role in analytical, biomedical, and separation‐based technologies. Depending on the application, protein–surface interactions may be exploited for selective capture or must be minimized to avoid nonspecific fouling. This review examines the fundamental mechanisms governing protein adsorption on solid surfaces, with emphasis on hydrophobic and electrostatic interactions, hydrogen bonding, π–π stacking, and confinement effects in porous materials. We discuss how material properties such as surface chemistry, porosity, and mineral composition influence protein binding, with particular focus on carbon‐based and inorganic solids. Strategies for controlling protein–surface interactions through surface functionalization, polymer modification, and affinity‐based approaches are critically reviewed. Special attention is given to molecularly imprinted polymers and aptamer‐functionalized materials as routes to introduce molecular selectivity beyond nonspecific adsorption. Finally, representative applications in biosensing, selective adsorption, and solid‐phase extraction are summarized, highlighting current capabilities and limitations of protein‐interactive materials in analytical workflows.
