Photochemical properties and interfacial fluorescence sensing for homocysteine of triptycene orthoquinone layer-by-layer-assembled multilayers

• A dual fluorescence probe for biological thiols was reported.
• This probe is based on triptycene orthoquinones self-assembled mutilayers.
• The sensor exhibits higher selectivity toward homocysteine than other thiol compounds.

In the present work, the properties of triptycene orthoquinone derivatives were studied. As a kind of good electron-transfer platform, triptycene derivatives with different electron donors or electron acceptors behave distinctively with their luminescent properties. The intensity ratio of fluorescence peaks can be controlled by the number of methoxy groups (electron donor) and orthoquinone groups (electron acceptor) simultaneously. We have assembled 6,7,12,13-4-methoxyl-2, 3-2-orthoquinone triptycene onto self-assembled monolayers (SAMs) to create a probe for detecting biological thiols. The SAMs exhibited higher selectivity toward homocysteine than to other thiol-containing compounds with a fast response and a stable signal over a wide liner range from 2.0 μmol/L to 1.0 mmol/L with the detection limit of 0.52 μmol/L.