Three benzothiazole derivatives, N-[4-(benzothiazol-2-yl)-3-hydroxyphenyl]-octanamide (BHPO1), N-[3-(benzothiazol-2-yl)-4-hydroxyphenyl]-octanamide (BHPO2), N-[4-(benzothiazol-2-yl)phenyl]-octanamide (BPO) were prepared and their luminescence properties were investigated. These analogues show similar absorption maxima but quite different emission regions due to the existence of an excited-state intramolecular proton transfer (ESIPT) process in BHPO1 and BHPO2. Upon excitation with 365 nm light, BPO, BHPO1 and BHPO2 exhibit bright blue-violet, green and orange emission in aggregated states, respectively which perfectly make up the component elements of white light. By doping these compounds into a polymer matrix at a certain proportion, an emission that lies at the saturated white-light region with CIE chromaticity coordinates of (0.31, 0.32) was obtained. This study provides a flexible and simple fabrication process of a white-light emitting device using three structurally-similar compounds without detrimental energy transfer.

•A bioluminogenic probe Glu-Luc was designed and synthesized by connecting D-luciferin with γ-glutamyl group.•The probe exhibits very high selectivity and sensitivity toward GGT activity from in vitro to in vivo and in clinical samples.•It offers a promising tool for investigations of the GGT-overexpressing related biological process including tumor diagnosis and prognosis in living organisms.Abnormal expression of γ-Glutamyltranspeptidase (GGT) in living organisms is closely implicated in the development of several human tumors. The GGT levels in tissue and serum have emerged as a potential criterion for tumor diagnosis. However, precise “light up” GGT activity in vivo is still challenging due to the signal interferes of background. Bioluminescence based on the firefly luciferase-catalyzed reaction for light production provides a feasible strategy for GGT detection in vivo. In this report, a bioluminogenic probe, Glu-Luc, was designed and synthesized by connecting D-luciferin with γ-glutamyl group. The cleavage of γ-glutamyl group is triggered by GGT, resulting in the release of D-luciferin, which generates a bright bioluminescence emission in the present of luciferase and ATP. The probe exhibits very high selectivity and sensitivity toward GGT activity from in vitro to in vivo and in clinical samples, which offers a promising tool for investigations of the GGT-overexpressing related biological process including tumor diagnosis and prognosis in living organisms.

•A novel “turn-on” two-photon fluorescent probe based on a π-conjugated triarylboron luminogen was designed and synthesized.•Fast, selective and sensitive detection of biothiols in 100% aqueous solution by simply loaded on a nanogel.•Single-photon and two-photon fluorescent bioimaging of biothiols in NIH/3T3 fibroblasts.A novel “turn-on” two-photon fluorescent probe containing a π-conjugated triarylboron luminogen and a maleimide moiety DMDP-M based on the photo-induced electron transfer (PET) mechanism for biothiol detection was designed and synthesized. By simply loading the hydrophobic DMDP-M on a cross-linked Pluronic® F127 nanogel (CL-F127), a probing system DMDP-M/CL-F127 was established, which shows quick response, high selectivity and sensitivity to cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) in aqueous phase. The DMDP-M/CL-F127 system presented the fastest response to Cys with a rate constant of 0.56 min−1, and the detection limit to Cys was calculated to be as low as 0.18 μM. The DMDP-M/CL-F127 system has been successfully applied to the fluorescence imaging of biothiols in NIH/3T3 fibroblasts either with single-photon or two-photon excitation because of its high biocompatibility and cell-membrane permeability. The present work provides a general, simple and efficient strategy for the application of hydrophobic molecules to sensing biothiols in aqueous phase, and a novel sensing system for intracellular biothiols fitted for both single-photon and two-photon fluorescence imaging.