A highly sensitive and selective rhodamine-semicarbazide based fluorescent sensor for Cu detection in real water samples and fluorescence bioimaging in HepG2 cells.

A colorimetric and fluorescent sensor, selective for Cu ions, was synthesized in two steps using a rhodamine-based compound attached to the semicarbazide-picolylamine moiety (RBP). Spectroscopic measurements, including UV-Vis absorption and fluorescence emission, were conducted in the semi-aqueous medium containing acetonitrile/4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, denoted as MeCN/HEPES buffer (2:8, v/v, pH 7.0).

Structural and mutational analysis of glycoside hydrolase family 1 Br2 -glucosidase derived from bovine rumen metagenome.

Ruminant animals rely on the activities of -glucosidases from residential microbes to convert feed fibers into glucose for further metabolic uses. In this report, we determined the structures of Br2, which is a glycoside hydrolase family 1 -glucosidase from the bovine rumen metagenome. Br2 folds into a classical (/)-TIM barrel domain but displays unique structural features at loop 5→5 and -helix 5, resulting in different positive subsites from those of other GH1 enzymes.

A Rhodamine-coumarin Triazole Conjugate as a Fluorescent Chemodosimeter for Cu(II) Detection and its Application in Live Cell Bioimaging.

A rhodamine-triazole fluorescent probe bearing a coumarin moiety RTC was synthesized using the Cu(I)-catalyzed click reaction. The rhodamine-triazole conjugate was highly selective to Cu among other metal ions, including Ca, Co, Cu, Cd, Mg, Fe, Fe, Hg, Zn, Ni, Pd and Pb in physiological conditions. Upon the addition of Cu, the colorless RTC solution turned pink and exhibited a significant fluorescence emission centered at 578 nm.

A Rhodamine-based Fluorescent Chemodosimeter for Au in Aqueous Solution and Living Cells.

A highly selective rhodamine hydrazide-based fluorescent chemosensor for Au detection was developed. The aqueous solution of rhodamine N-hydroxysemicarbazide (RHS), in the presence of Au, exhibited a significant 55-fold turn-on fluorescence response at 591 nm and a colorimetric change from colorless to pink. Other interested ions including Li, Na, K, Cs, Mg, Ca, Ba, Pb, Mn, Co, Ni, Ag, Cd, Cu, Hg, Zn, Sn, Fe, Fe, Cr, Ce did not induce any distinct color/spectral changes.