A 1,8-naphthalimide derivative (1) was intentionally designed and synthesized as a new turn-on fluorescent probe for the detection of zinc ion with high selectivity over other metal ions at pH 7.4 in aqueous media (CH3CN/HEPES, V/V = 6:4). The reaction mechanism is attributed to the replacement of the protons of the O–H groups by zinc ion at the binding site and production of fluorescence which is blocked in the photo-induced electron transfer (PET) process. Remarkable enhancement of up to 13-fold in fluorescence intensity with a 38 nm red-shift was achieved in the detection of zinc ion. Compound 1 was successfully applied to the fluorescence imaging of zinc ion, with a fluorescence emission color produced in the cell nucleus different from that produced in the cytoplasm, in A549, BEAS-2B, CHO, Hela, and HepG2 cells. Furthermore, cytokinesis-block micronucleus (CBMN) assay was carried out in CHO cells using 1 and zinc ion as the imaging agents, showing that the 1-Zn2+ agent is a nucleic acid selective stain, which could be applied in MN assays in different kinds of cell lines.A 1,8-naphthalimide derivative (1) was intentionally designed and synthesized as a new turn-on fluorescent probe for the detection of zinc ion in aqueous media (CH3CN/HEPES, V/V = 6:4). Remarkable enhancement of up to 13-fold in fluorescence intensity with a 38 nm red-shift was achieved in the detection of zinc ion. Compound 1 was successfully applied to the fluorescence imaging of zinc ion, with a fluorescence emission color produced in the cell nucleus different from that produced in the cytoplasm, in A549, BEAS-2B, CHO, Hela, and HepG2 cells. Furthermore, cytokinesis-block micronucleus (CBMN) assay was carried out in CHO cells using 1 and zinc ion as the imaging agents, showing that the 1-Zn2+ agent is a nucleic acid selective stain, which could be applied in MN assays in different kinds of cell lines.

A 1,8-naphthalimide–Cu(II) ensemble was rationally designed and synthesized as a new turn-on fluorescent probe utilizing the ‘chemosensing ensemble’ method for detections of thiols (Cys, Hcy and GSH) with high selectivity over other α-amino acids at pH 7.4 in organic aqueous media (EtOH/HEPES, v/v = 9:1). The recognition mechanism was attributed to the remove Cu(II) from the 1,8-naphthalimide–Cu(II) ensemble by thiols and the release of flurescence of ligand 1. Remarkable fluorescence enhancements were therefore observed in the sensing process of thiols by the 1,8-naphthalimide–Cu(II) ensemble. Furthermore, the 1,8-naphthalimide–Cu(II) ensemble was successfully applied to the fluorescence imaging of thiols in CHO cells with high sensitivity and selectivity.A naphthalimide–Cu(II) ensemble was rationally designed and synthesized as a new turn-on fluorescent probe utilizing the ‘chemosensing ensemble’ method for detections of thiols (Cys, Hcy and GSH) with high selectivity over other α-amino acids. The recognition mechanism was attributed to the remove of Cu(II) from the naphthalimide–Cu(II) ensemble by thiols and the release of florescence of ligand 1. Remarkable fluorescence enhancements were therefore observed in the sensing process of thiols by the naphthalimide–Cu(II) ensemble in the vitro assays and in the fluorescence imaging in CHO cells with high sensitivity and selectivity.

A 1,8-naphthyridine modified rhodamine B derivative (1) has been designed and synthesized. Compound 1 is the first 1,8-naphthyridine-modified rhodamine B sensor that can detect Cu2+ selectively with a dramatic color change from colorless to pink. The complex of 1 and Cu2+ was utilized as a chemosensing ensemble for cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) detection, which showed highly sensitive and selective colorimetric response to Cys, Hcy, and GSH among the tested naturally occurring α-amino acids in EtOH-HEPES (0.02 M, pH 7.4) (3:7, v/v) buffer solution.A 1,8-naphthyridine modified rhodamine B derivative (1) has been designed and synthesized. Compound 1 is the first 1,8-naphthyridine-modified rhodamine B sensor that can detect Cu2+ selectively with a dramatic color change from colorless to pink. The complex of 1 and Cu2+ was utilized as a chemosensing ensemble for cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) detection, which showed highly sensitive and selective colorimetric response to Cys, Hcy, and GSH among the tested naturally occurring α-amino acids in EtOH-HEPES (0.02 M, pH 7.4) (3:7, v/v) buffer solution.