Rapid and selective detection of selenocysteine with a known readily available colorimetric and fluorescent turn-on probe

Selenocysteine (Sec) is known as the 21st amino acid that is incorporated into selenoproteins (SePs) and plays vital roles in living systems. Accordingly, development of fluorescent detection method for Sec is of significance. Herein, a readily available fluorescent Sec probe is reported. Although this probe has been reported before for detection of biothiols, the studies in this work show that it can be used for rapid, high selective and sensitive detection of Sec over biothiols and many other analytes with dual colorimetric and fluorescent turn-on signal changes simply by slightly changing the detection conditions. The detection limit of this probe for Sec was found to be about 47 nM with a wide linear range (0-80 mu M). In addition, this probe has low cytotoxicity and is able to detect Sec in serum samples and in living cells, indicating it can be used as a potential new molecular tool for Sec detection.