NIR Fluorophores in Practical Analytical Chemistry

Swamy, Anand R.; George, Abraham; Tarazi, Leila; Patonay, Gábor; Strękowski, Lucjan

doi:10.1007/978-94-011-5102-3_9

Near-Infrared Dyes for High Technology Applications 1998

DOI: 10.1007/978-94-011-5102-3_9

|View full text |Cite

NIR Fluorophores in Practical Analytical Chemistry

Anand R. Swamy

Abraham George

Leila Tarazi

et al.

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

2004

Publication Types

Select...

Article1

Relationship

Self Cite1

Independent0

Authors

Journals

Cited by 1 publication

(1 citation statement)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The direct spectral measurements are possible because few natural products show absorption above 650 nm and, as a result, any biological medium is extensively penetrated by near-infrared radiation [3]. Recently, covalent and non-covalent labeling of biological macromolecules with a near-infrared chromophore has become a firmly established trend in bioanalytical research [3][4][5][6].Due to their limited solubility, the two pH-sensitive dye systems mentioned above have found little application. In continuation of our research we now report for the first time the synthesis of a series of ketone/cyanine compounds that are water soluble.…”

mentioning

confidence: 99%

Water‐soluble pH‐sensitive 2,6‐bis(substituted ethylidene)‐cyclohexanone/hydroxy cyanine dyes that absorb in the visible/near‐infrared regions

Strękowski

Mason

Say

et al. 2004

Journal of Heterocyclic Chem

Self Cite

View full text Add to dashboard Cite

Three methods were used to synthesize a series of the title compounds. The ketones absorb in the visible region, and upon protonation (pH<6) they are converted to hydroxy-substituted heptamethine cyanines that show an intense absorption in the near-infrared region (>700 nm). The conversion is reversible and depends solely on pH conditions. J. Heterocyclic Chem., 41, 227 (2004).A decade ago we reported for the first time a novel pHsensitive dye system 1=O/1-OH shown in equation 1 [1]. Ketone 1=O exhibits absorption in the visible region (λ max = 535 nm), and upon protonation it is transformed into hydroxy cyanine 1-OH with an intense absorption in the n e a r-infrared region (λ m a x = 709 nm). This change is reversible and depends solely on pH conditions. A related dye (not shown) has been described by us more recently [2]. The search for new pH-sensitive dyes that absorb in the near-infrared region of the electromagnetic spectrum (>650 nm) has been stimulated by potential application of such indicators in bioanalytical chemistry. When complexed or covalently attached to a protein, the pH-sensitive label can act as a pH-dependent reporter molecule in a complex biological material by using non-invasive spectroscopic detection. The direct spectral measurements are possible because few natural products show absorption above 650 nm and, as a result, any biological medium is extensively penetrated by near-infrared radiation [3]. Recently, covalent and non-covalent labeling of biological macromolecules with a near-infrared chromophore has become a firmly established trend in bioanalytical research [3][4][5][6].Due to their limited solubility, the two pH-sensitive dye systems mentioned above have found little application. In continuation of our research we now report for the first time the synthesis of a series of ketone/cyanine compounds that are water soluble. The previous chemistry [1,2] is evaluated, and an improved synthetic methodology is presented.The structures of new pH-sensitive compounds are given in Scheme 1. For the sake of clarity of presentation, only the cyanine forms (9-OH -12-OH, 15-OH) are shown. As can be seen, all these dyes are N-substituted with hydrophilic sulfoalkyl groups, additional two sulfo groups are attached to the aromatic subunits of 1 0 -O H, and an additional carboxylic acid function is present in 15-OH. Chloro cyanines 9-Cl -13-Cl served as precursors to the final products. The cyanines 9-Cl -13-Cl were efficiently synthesized by condensation of indolium derivatives 2-6 with Vilsmeier-Haack reagents 7 or 8. This is a classical preparation that is conveniently conducted in ethanol in the presence of sodium acetate as a base [7]. The conversion of substrates 9-Cl -13-Cl to the corresponding pH-sensitive dyes is summarized in Table 1 and discussed as follows.The Sodium-Acetate Method.

show abstract

mentioning

confidence: 99%

Water‐soluble pH‐sensitive 2,6‐bis(substituted ethylidene)‐cyclohexanone/hydroxy cyanine dyes that absorb in the visible/near‐infrared regions

Strękowski

Mason

Say

et al. 2004

Journal of Heterocyclic Chem

Self Cite

View full text Add to dashboard Cite

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

NIR Fluorophores in Practical Analytical Chemistry

Cited by 1 publication

References 10 publications

Water‐soluble pH‐sensitive 2,6‐bis(substituted ethylidene)‐cyclohexanone/hydroxy cyanine dyes that absorb in the visible/near‐infrared regions

Water‐soluble pH‐sensitive 2,6‐bis(substituted ethylidene)‐cyclohexanone/hydroxy cyanine dyes that absorb in the visible/near‐infrared regions

Contact Info

Product

Resources

About