New blue light-emitting isocyanobiphenyl based fluorophores: Their solvatochromic and biolabeling properties

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Vol. 318; pp. 124 - 134
• Main Authors: Nagy, Miklós, Rácz, Dávid, Kovács, Sándor Lajos, Lázár, László, Fehér, Péter Pál, Purgel, Mihály, Zsuga, Miklós, Kéki, Sándor
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2016
• Subjects: BSA; DFT; Fluorescence; Isocyanobiphenyl; Solvatochromism; Fluorescence; Solvatochromism; BSA; Isocyanobiphenyl; DFT
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2015.12.006

[Display omitted] •New, blue light-emitting isocyanobiphenyl based fluorophore family was developed.•They can be a cheap, easy to prepare alternative to commercial solvatochromes.•The ICAB derivatives turned out to be efficient biolabeling agents with BSA.•Simultaneous static and dynamic quenching were observed with pyridine.•High-level DFT calculations was applied to describe the fluorescence behavior. The preparation and optical study of 4-amino-4′-isocyanobiphenyl (ICAB) and its mono-and dialkylated derivatives (monoMICAB and diMICAB) are reported. They were found to be effective blue light emitters with a solvatochromic range of Δλmax=104nm, 92nm and 90nm, respectively. All three compounds turned out to be promising candidates in protein-labeling, yielding ∼70–190× increase in their fluorescence intensity when mixed with 10× molar excess of bovine serum albumin (BSA). The binding constants for the BSA-fluorophore complexes were found to be KICAB-BSA=3.8×104±5.7×103M−1, KmonoMICAB-BSA=6.0×104±3.9×103M−1 and KdiMICAB-BSA=2.3×104±3.2×103M−1. Time resolved fluorescence measurements revealed a nearly uniform ∼2ns lifetime for all three BSA-complexed ICAB derivatives.