Highly Fluorescent and Water‐Soluble Diketopyrrolopyrrole Dyes for Bioconjugation

Abstract

The preparation of highly water-soluble and strongly fluorescent diketopyrrolopyrrole (DPP) dyes using an unusual taurine-like sulfonated linker has been achieved. Exchanging a phenyl for a thienyl substituent shifts the emission wavelength to near l = 600 nm. The free carboxylic acid group present in these new derivatives was readily activated and the dyes were subsequently covalently linked to a model protein (bovine serum albumin; BSA). The bioconjugates were characterized by electronic absorption, fluorescence spectroscopy and MALDI-TOF mass spectrometry, thus enabling precise determination of the labeling density (ratio DPP/BSA about 3 to 8). Outstanding values of fluorescence quantum yield (30 % to 59 %) for these bioconjugates are obtained. The photostability of these DPP dyes is considerably greater than that of fluorescein under the same irradiation conditions. Remarkably low detection limits between 80 and 300 molecules/mm 2 were found for the BSA bioconjugates by fluorescence imaging with a epifluorescence microscope.

Using Native Chemical Ligation for Site‐Specific Synthesis of Hetero‐bis‐lanthanide Peptide Conjugates: Application to Ratiometric Visible or Near‐Infrared Detection of Zn2+

“…screening, we assessed the potential of five antennas for the sensitization of NIR-emitting Ln 3 + through various chromophores absorbing in the UV or the visible ranges ( Figure 5B): 4-(dimethylamino)-1,8-naphthalimide (4-DMN, l max = 447 nm), 1amino-anthraquinone (AAQ, l max = 505 nm), 7-(diethylamino)coumarin (DEAC, l max = 433 nm), aw ater-solubled erivative of 3,6-diphenyl-diketopyrrolopyrrole [48] (DPP, l max = 455 nm), and anthracene (Anthra, l max = 369 nm). The experimental procedures for the synthesis of thev arious LZF1 Antenna j Ln or LZF3 Antenna j Ln (Ln = Nd and Yb) peptides are described in the Supporting Information.…”

Highly Sensitive Thin-Film Field-Effect Transistor Sensor for Ammonia with the DPP-Bithiophene Conjugated Polymer Entailing Thermally Cleavable tert-Butoxy Groups in the Side Chains

“…Solvents and other common reagents were obtained from Beijing Chemical Co. DPPBu (Scheme 2) was synthesized according to the reported literature. 63 1 H NMR and 13 C NMR spectra were measured on a Bruker AVANCE III 400 and 500 MHz spectrometers. Elemental analysis of carbon, hydrogen, sulfur and nitrogen was performed on a Carlo Erba model 1160 elemental analyzer.…”

“…The synthesis of 2BrDPPBu started from 3,6-di(thiophen-2-yl)pyrrolo [3,4-c]pyrrole-1,4(2H,5H)dione (DPP), which was transformed into DPPBu after reaction with tert-butyl bromoacetate and K 2 CO 3 in DMF according to previous report. 63 Then, reaction of DPPBu and N-bromosuccinimide (NBS) yielded 2BrDPPBu in 88% yield. The Stille coupling of 2BrDPPBu and 4,4′-didodecyl-[2,2′bithiophene]-5,5′-diyl)bis(trimethylstannane) was successfully carried out in the presence of Pd 2 (dba) 3 and P(o-tolyl) 3 as the catalyst and ligand, respectively.…”

Near-infrared emissive bacteriochlorin-diketopyrrolopyrrole triads: Synthesis and photophysical properties

“…To a suspension of 3,6-diphenyl-DPP pigment [60] (100 mg, 0.35 mmol, 1.0 equiv), TBACl (5.0 mg, 17.3 µmol, 0.05 equiv) and K2CO3 (264 mg, 1.91 mmol, 5.5 equiv) in DMF (5 mL), 1-chloro-2-(2-(2-methoxyethoxy)ethoxy)ethane [60] (633 mg, 3.47 mmol, 10.0 equiv) was added dropwise, at 120 °C and under argon. The resulting reaction mixture was heated at 120 °C overnight.…”