Xin-Dong Jiang

A turn-on NIR fluorescent probe for the detection of homocysteine over cysteine

A BODIPY-based turn-on NIR fluorescent probe containing a partially exposed aldehyde group at the meso position for the detection of homocysteine over cysteine was developed. Such a probe is potentially useful for the discrimination of Hcy from Cys.

Synthesis of mono-(p-dimethylamino)styryl-containing BOPHY dye for a turn-on pH sensor

Mono-substitutional bis(difluoroboron)1,2-bis((1H-pyrrol-2-yl)methylene)hydrazine (BOPHY) 3a with a (p-dimethylamino)styryl group in the α-position was confirmed to be synthesized by the Knoevenagel-type condensation. Dimethylamino-containing BOPHY dye 3a is almost non-fluorescent by the ICT effect. Upon the protonation of the tertiary amine function of 3a, the strong fluorescence (Φf = 0.98) was released and the fluorescence intensity was dramatically increased by one thousand fold. BOPHY 3a can be used as a pH probe.

A New Water-Soluble Phosphorus-Dipyrromethene and Phosphorus-Azadipyrromethene Dye: PODIPY/aza-PODIPY

PODIPY and aza-PODIPY have been successfully prepared by the treatment of dipyrromethene and azadipyrromethene with POCl3 in the presence of Et3 N. The new PODIPY and aza-PODIPY dyes are found to have photophysical properties. PODIPY and aza-PODIPY are water-soluble, and aza-PODIPY is suited for labeling living Hep-2 cells for imaging assays in the near-infrared region. Molecular orbital calculations show that the increase in the HOMO-LUMO band gap for the lowest energy absorption bands is observed in the new phosphorus-containing aza-PODIPY, and the HOMO and LUMO energies of aza-PODIPY are found to be higher than those of aza-BODIPY.

A styryl-containing aza-BODIPY as a near-infrared dye

A novel styryl-containing pyrrole was developed by the reaction of E-4-phenylbut-3-en-2-one with 3-phenyl-2H-azirine in the presence of LDA. Utilizing this pyrrole, asymmetric styryl-containing aza-BODIPYs have been prepared in the NIR region as a result of the combined extension of conjugation. This styryl-containing aza-BODIPY was bright enough to be suited to label living cells for imaging assays in the NIR region.

Singlet oxygen generation properties of isometrically dibromated thienyl-containing aza-BODIPYs

Isometrically dibromated thienyl-containing aza-BODIPYs CDB-1 and BDB-2 with potential use as photosensitizers (PSs) were successfully prepared and their photophysical properties were fully characterized. Singlet oxygen generation experiments were also performed. In this regard, PS CDB-1 was found to be more effective and had about two-fold rate enhancement compared to PS BDB-2. DFT and TD-DFT calculations helped to provide insights into the distinct intersystem crossing (ISC) processes observed for CDB-1 and BDB-2.