Aldehyde bearing bis-cyclometalated Ir(III) complex as selective photoluminescence turn-on probe for imaging intracellular homocysteine

Abstract

A new photoluminescence (PL) turn-on probe based on aldehyde bearing bis-cyclometalated Ir(III) complex, [Ir(bt) 2 phen-CHO] + PF 6-(1), is synthesized and applied to imaging homocysteine (Hcy) in living cells. The probe 1 is readily prepared by using 2-phenylbenzothiazole (bt) as main ligand and 1,10-phenanthroline-5-carboxaldehyde (phen-CHO) as ancillary ligand. Probe 1 displayed excellent selective PL enhancement in response to Hcy in neutral buffer solution based on aldehyde group cyclization reaction. The increased PL intensity of probe 1 is directly proportional to the concentration of Hcy in the range of 10 μM to 500 μM with a detection limit of 4.6 μM. More importantly, probe 1 can highly discriminate Hcy from cysteine (Cys), which is agreed with the higher luminescent quantum yield of the adduct of probe 1 and Hcy (1-Hcy, 0.46) compared with that of probe 1 and Cys (1-Cys, 0.05) in 10 mM phosphate buffer solution (pH 7.4). Furthermore, the probe 1 has appreciable cell permeability and low cytotoxicity and has been successfully applied to selectively imaging Hcy in living cells. The superior properties of the probe 1 make it of great potential use for studying the effects of Hcy in other biosystems.

New Fast, Highly Selective Probe with Both Aggregation-Induced Emission Enhancement and Intramolecular Charge-Transfer Characteristics for Homocysteine Detection

“…The formed ring affects the transfer of electrons, thus causing changes in fluorescence intensity and ultraviolet light. The possible sensing mechanism and binding mode of probe DBTC with Hcy are shown in Figure , which was consistent with the reported results. − …”

An Intramolecular Charge Transfer and Aggregation Induced Emission Enhancement Fluorescent Probe Based on 2‐Phenyl‐1,2,3‐triazole for Highly Selective and Sensitive Detection of Homocysteine and Its Application in Living Cells

“…In order to explain and confirm the binding mechanism between APTC and Hcy in more depth, the peak at m / z = 466.2134 belongs to the product of [APTC+Hcy], which was evidently observed by mass spectrometry (Figure S8). The plausible binding way of APTC with Hcy was revealed in Figure , which was the same as reported in previous literatures …”

Electrogenerated Chemiluminescent Chemodosimeter Based on a Cyclometalated Iridium(III) Complex for Sensitive Detection of Thiophenol

“…Therefore, it was expected that 2 -PhS – would produce TPrA • more efficiently than 1 -PhS – via a smooth catalytic process. Ir­(III) complexes with a formyl group on the main ligand exhibited weaker PL intensities compared to those without a formyl group. ,− As expected, 2 -PhS – exhibited much weaker PL intensity than 1 -PhS – . However, the ECL intensity of 2 -PhS – was comparable to that of 1 -PhS – , which could be explained by the smooth catalytic process of 2 -PhS – (Figure S10).…”