Journal of Photochemistry and Photobiology A: Chemistry 240 (2012) 26–32 Contents lists available at SciVerse ScienceDirect Journal of Photochemistry and Photobiology A: Chemistry journa l h o me pag e: www.elsevier.com/locate/jphotochem Hg 2+ -selective “turn-on” fluorescent chemodosimeter derived from glycine and living cell imaging Ajit Kumar Mahapatra a,∗ , Jagannath Roy a , Saikat Kumar Manna a , Supratim Kundu a , Prithidipa Sahoo b , Subhra Kanti Mukhopadhyay c , Avishek Banik c a Department of Chemistry, Bengal Engineering and Science University, Shibpur, Howrah 711 103, India b Chemistry and Chemical Biology Department, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854, USA c Department of Microbiology, The University of Burdwan, Burdwan, West Bengal, India a r t i c l e i n f o Article history: Received 5 January 2012 Received in revised form 14 March 2012 Accepted 1 May 2012 Available online 9 May 2012 Keywords: Fluorescent chemodosimeter Glycine Mercury Turn-on fluorescent probes Pollen cell a b s t r a c t A new nonfluorescent benzthiazole derivative of dithio-N-phthaloylglycine was prepared, and its fluorogenic chemodosimetric behaviors toward transition metal ions were investigated. The dithio-N- phthaloylglycine derivative showed highly Hg 2+ -selective fluorescence enhancing (“turn-on”) properties in 20% aqueous acetonitrile solution (H 2 O/CH 3 CN = 80:20, v/v). The chemodosimetric behavior is based on the Hg 2+ triggered desulfurization of dithio-N-phthaloylglycine derivative into its oxygen analogue. To observe the cell permeability of 3 into Pollen grains, we also employed it for the fluorescence detection of the changes of intracellular Hg 2+ in cultured cells. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Mercury is one of the most dangerous and widespread global pollutant [1,2], as seen in such unfortunate incidents as Mina- mata disease [3] and mercury poisoning in Iraq [4]. As these cases showed, methylmercury is extremely toxic to aquatic organisms and birds than inorganic mercury, which eventually reaches the top of the food chain and accumulates in higher organisms, especially in large edible fish [5]. When consumed by humans, methylmer- cury triggers several serious disorders including sensory, motor, and neurological damage. The development of methods for the determination mercury is, therefore, of significant importance for environment and human health. Traditional analytical techniques for Hg 2+ include atomic absorption spectroscopy, cold vapor atomic fluorescence spectrometry and gas chromatography. These meth- ods, however, require not only complicated instrumentation but also a long measuring time. Therefore, it is urgent to develop new methods for monitoring Hg 2+ with a low limit of detection, as well as rapid and facile detection. In particular, fluorescence has been regarded as the most powerful optical technique for detect- ing low concentrations of metal ions, and considerable efforts have been devoted to the development of fluorescent chemical sensors ∗ Corresponding author. Tel.: +91 33 2668 4561; fax: +91 33 26684564. E-mail address: mahapatra574@gmail.com (A.K. Mahapatra). that detect mercury ions [6–9]. Among them, a chemodosimet- ric approach frequently yields successful results in the selective and sensitive signaling of Hg 2+ ions [10–15]. Hg 2+ -triggered desul- furization and/or transformation of thioamide [16], selenolactone [17] and thione has been successfully utilized for the development of Hg 2+ -selective chemodosimeters, beginning with the classi- cal anthracene-based dosimeter [18] developed by Czarnik and coworkers. These methods may facilitate mercury analyses by the conver- sion of thiocarbonyl compounds into their carbonyl analogues via oxidative procedures that involve inorganic and organic reagents, as well as hydrolytic reactions [19]. Because mercury is a soft Lewis acid, a vast majority of the chemosensors and chemodosimeters for mercury contain sulfur atom(s) that can tightly coordinate the metal, thus weakening the C S bond and as part of off–on fluo- rescence switches. So the probes for Hg 2+ generally consist of a chromophore and a reactive region that can be chelated [20–22] or reacted [16,23–30] with Hg 2+ ions. The absorption or emission properties of the probes change with the interactions between the reactive region and Hg 2+ ions. The development of novel chromophores with appropriate reactive regions for selective, sen- sitive detection remains an important goal for ion sensors. During our ongoing research on both cation [31,32] and anion [33,34] recognition, herein, we report the synthesis and application of a probe based on benzthiazole, 2-benzthiazol-2-ylmethylisoindole- 1,3-dithione (3), for the selective, sensitive detection of Hg 2+ ions in 1010-6030/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jphotochem.2012.05.001