New near infrared absorbing acidochromic dyes and their application in sensor techniques

Lindauer, Heike; Czerney, Peter; Mohr, Gerhard J.; Grummt, U.‐W.

doi:10.1016/0143-7208(94)80038-3

Cited by 17 publications

(3 citation statements)

References 4 publications

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“…Among other important features, as previously mentioned, these dyes must comprise substituents that block the hydration of the flavylium cation, leading to improved stability in biorelevant media. Earlier work performed in the 1990s already indicated the potential of these chromophores for use as fluorescent lasers and near-infrared dyes. − More recently, flavylium-based fluorescent probes have reemerged in different studies focused in the development of dyes with imaging applications, although they are not always identified as flavylium compounds. , In the following paragraphs, two representative examples are described to illustrate the potential of these compounds in the field.…”

Section: Photochromic Propertiesmentioning

confidence: 99%

Natural and Synthetic Flavylium-Based Dyes: The Chemistry Behind the Color

et al. 2021

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Flavylium compounds are a well-known family of pigments because they are prevalent in the plant kingdom, contributing to colors over a wide range from shades of yellow-red to blue in fruits, flowers, leaves, and other plant parts. Flavylium compounds include a large variety of natural compound classes, namely, anthocyanins, 3deoxyanthocyanidins, auronidins, and their respective aglycones as well as anthocyaninderived pigments (e.g., pyranoanthocyanins, anthocyanin-flavan-3-ol dimers). During the past few decades, there has been increasing interest among chemists in synthesizing different flavylium compounds that mimic natural structures but with different substitution patterns that present a variety of spectroscopic characteristics in view of their applications in different industrial fields. This Review provides an overview of the chemistry of flavylium-based compounds, in particular, the synthetic and enzymatic approaches and mechanisms reported in the literature for obtaining different classes of pigments, their physical-chemical properties in relation to their pH-dependent equilibria network, and their chemical and enzymatic degradation. The development of flavylium-based systems is also described throughout this Review for emergent applications to explore some of the physical-chemical properties of the multistate of species generated by these compounds.

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Section: Photochromic Propertiesmentioning

confidence: 99%

Natural and Synthetic Flavylium-Based Dyes: The Chemistry Behind the Color

et al. 2021

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“…1. Because of their pH-indicating properties and their solubility in plasticized PVC they can act as pH sensors [20] as well as transducers for enzyme reactions during which a change in pH occurs [21]. While studying this dye it was noticed that ethanol solutions of dye L-1 undergo a colour change from blue to pink on addition of silver nitrate.…”

Section: Dye and Sensing Schemementioning

confidence: 98%

Optode membrane for continuous measurement of silver ions

et al. 1995

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Abstract. An optical sensor (optode) membrane for continuous monitoring of silver ion is presented. It is composed of plasticized poly(vinyl chloride) (PVC), a silver-sensitive chromo-ionophore, and a lipophilic borate salt acting as an anionic site. The membrane selectively responds to silver ion in the concentration range from 50 pM to 10 raM, giving a reversible colour change from blue to pink, with response times of the order of 2 min. The acridinium dye acts as both the recognition element and the chromo-ionophore. Its long-wave absorption band is at around 680 nm, which makes it compatible with existing LED light sources and diode lasers. A lipophilic octadecyl side chain renders it highly lipophilic and this prevents its leakage out of the PVC membrane. Hence, the operational lifetime exceeds 1 week, without any changes in the work function.Key words: silver sensor, optical sensors, chromo-ionophore, spectrophotometry, PVC membrane.Silver is widely used in conventional photography, the production of electrical conductors, and in electroplating. It has been estimated that the total annual loss of silver to the environment from industrial wastes exceeds 2500 metric tons [1], a fact that clearly points to the importance of monitoring and recycling of silver, both from a commercial and an environmental point of view.Numerous analytical procedures (including single-shot tests and field tests) have been described for determination of silver. However, in order to enable continuous monitoring, sensors rather than discontinuous methods are required. Among them, solid-state sensors based on silver sulphide are predominant. In addition, electrochemical ion-selective sensors (ISEs and ISFETs) based on plasticized PVC membranes, modified with various silver-selective ionophores such as thia-crown ethers [2][3][4][5][6][7], calixarenes [8,9], and pyridinophanes [10] have been reported. The

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“…Cyanine dyes are promising sensing reagents because the resonance interaction of the chromophore can be affected by reaction with alkaline substances, or can be protonated in reactions with acid substances. 10,11 Nitroso dyes have appropriate absorption features for use in fibre optic sensors and their structure suggests that their chromophoric system might be affected by the presence of H + ions; however, it appears that nitroso dyes have not been evaluated for chemical sensing applications before.…”

Section: Introductionmentioning

confidence: 99%