3-[Bis(pyridin-2-ylmethyl)amino]-5-(4-carboxyphenyl)-BODIPY as Ratiometric Fluorescent Sensor for Cu2+

Abstract

We developed an asymmetric fluorescent sensor 1 for Cu2+, based on 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY), by introducing 4-carboxyphenyl and bis(pyridin-2-ylmethyl)amine groups at the 5- and 3-positions, respectively, of the BODIPY core. We then investigated the photophysical and cation-sensing properties of the sensor. BODIPY 1 showed large absorption and fluorescence spectral shifts on binding to Cu2+. The fluorescence peak at 580 nm red-shifted to 620 nm. The binding stoichiometry of BODIPY 1 and Cu2+ was 1:3. The ratio of the fluorescence intensity at 620 nm to that at 580 nm (F620/F580) increased with increasing concentration of Cu2+ (3–10 equiv); this enabled ratiometric determination of Cu2+. Although BODIPY 1 showed good selectivity for Cu2+, there was an interfering effect of Fe3+. BODIPY 1 could be used for the naked-eye detection of Cu2+ in a water-containing sample.

An NIR Emissive Donor-π-Acceptor Dicyanomethylene-4H-Pyran Derivative as a Fluorescent Chemosensor System towards Copper (II) Detection

“…DPA-based sensors for Cu 2+ with several different fluorophores have been reported, including ruthenium (II) [7,8] and iridium (II) [9] complexes, naphthalimide [10][11][12], chalcones [13] and BODIPY dyes [14,15], among others [16].…”

A highly sensitive “ON–OFF–ON” dual optical sensor for the detection of Cu(ii) ion and triazole pesticides based on novel BODIPY-substituted cavitand

“…[28][29][30] Their exceptional photophysical properties, strong UV-absorbance, sharp fluorescence emission peaks, good solubility in numerous solvents, relative insensitivity towards polarity and pH variation along with rational stability under physiological conditions, make from these fluorescent dyes apposite agents for heavy metal and pesticide recognition. [31][32][33][34] Although numerous examples of cavitand derivatives have been reported in literature, few studies on these two groups (cavitand + BODIPY) combined are reported, [35][36][37][38] and to the best of our knowledge, there have been no report thus far describing the utility of such ionophore-fluorophore conjugates for heavy metal and pesticide recognitions on the cavitand derivatives.…”