02218nas a2200217   4500008004100000245009700041210006900138260000800207300001600215490000700231520147200238100002401710700002401734700001901758700001901777700002301796700002401819700002501843700001701868856011501885       2016                        eng d00aSwitch-on NIR probe for specific detection of Hg2+ ion in aqueous medium and in mitochondria0 aSwitchon NIR probe for specific detection of Hg2 ion in aqueous   cNOV  a12052-120600 v553 aA new 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-based probe molecule (L) is synthesized for specific binding to Hg2+ ion in physiological condition with an associated luminescence ON response in the near-IR region of the spectrum. Appropriate functionalization in the 5-position of each of two pyrrole moieties with styryl functionality in a BODIPY core helped us in achieving the extended conjugation and a facile intramolecular charge transfer transition with a narrow energy gap for frontier orbitals. This accounted for a poor emission quantum yield for the probe molecule L. Binding to. Hg2+ helped in interrupting the facile intramolecular charge transfer (ICT) process that was initially operational for L. This resulted in a hypsochromic shift of absorption band and a turn-on luminescence response with lambda(Em)(max) of 650 nm on specific binding to Hg2+. Observed spectral changes are rationalized based on quantum chemical calculations. Interestingly, this reagent is found to be localized preferentially in the mitochondria of the live human colon cancer (Hct116) cells. Mitochondria is one of the major targets for localization of He2+, which actually decreases the mitochondrial membrane potential and modifies various proteins having sulfudryl functionality(ies) to cause cell apoptosis. Considering these, ability of the present reagent to specifically recognize Hg2+] in the mitochondrial region of the live Hct116 cells has significance.1 aAgarwalla, Hrideshg1 aMahajan, Pankaj, S.1 aSahu, Debashis1 aTaye, Nandaraj1 aGanguly, Bishwajit1 aMhaske, Santosh, B.1 aChattopadhyay, Samit1 aDas, Amitava  uhttps://library.ncl.res.in/content/switch-nir-probe-specific-detection-hg2-ion-aqueous-medium-and-mitochondria