Modern reaction-based indicator systems

Abstract

Traditional analyte-specific synthetic receptors or sensors have been developed on the basis of supramolecular interactions (e.g., hydrogen bonding, electrostatics, weak coordinative bonds). Unfortunately, this approach is often subject to limitations. As a result, increasing attention within the chemical sensor community is turning to the use of analyte-specific molecular indicators, wherein substrate-triggered reactions are used to signal the presence of a given analyte. This tutorial review highlights recent reaction-based indicator systems that have been used to detect selected anions, cations, reactive oxygen species, and neutral substrates.

In vivo bioluminescence imaging of labile iron accumulation in a murine model of Acinetobacter baumannii infection

“…In this regard, detection of iron with both metal and oxidation state specificity is of central importance, because while iron is stored primarily in the ferric oxidation state, a ferrous iron pool loosely bound to cellular ligands, defined as the labile iron pool (LIP), exists at the center of highly regulated networks that control iron acquisition, trafficking, and excretion. Indeed, as a weak binder on the Irving-Williams stability series (13), Fe 2+ provides a challenge for detection by traditional recognition-based approaches (14), and as such we (15)(16)(17) and others (18)(19)(20) have pursued activity-based sensing approaches to detect labile Fe 2+ stores in cells (21)(22)(23)(24)(25). These tools have already provided insights into iron biology, as illustrated by the direct identification of elevations in LIPs during ferroptosis (26,27), an emerging form of cell death, using the ratiometric iron indicator FIP-1 (15).…”

A Self‐Powered Polymeric Material that Responds Autonomously and Continuously to Fleeting Stimuli

“…The microsphere also contains an activity-based detection reagent [6] (e.g., reagent 1 in Figure 1 and Scheme 1 a) that detects a predefined stimulus through reaction of a specific functionality with the stimulus. In principle, this activitybased detection reagent can be exchanged with other functionalities to create modular materials that respond to a variety of fleeting stimuli.…”

“…In principle, this activitybased detection reagent can be exchanged with other functionalities to create modular materials that respond to a variety of fleeting stimuli. [6] Reagent 1 in Scheme 1 a is designed to respond to light with wavelengths of 254 nm to 365 nm [7] and release two equivalents of fluoride, carbon dioxide, 4-aminobenzaldehyde derivative 3, and two protons (Scheme 1 b). The released fluoride is a signal transduction reagent (represented by the purple squares in Figure 1) that translates the detection event into the initiation of a self-propagating reaction.…”

A novel long-wavelength fluorescent probe for discrimination of different palladium species based on Pd-catalyzed reactions

“…[1][2][3][4][5] The concern of palladium for human health and environmental contamination is increasing and a lot of attention has been paid to it recently. 6 In particular, palladium could bind to thiol-containing proteins, DNA, and other biomolecules, causing potential toxicity and carcinogenicity to humans, and it is strongly limited by governmental regulations to 5-10 ppm in end products.…”