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A novel BODIPY-based colorimetric and fluorescent sensor with an attached urea group ( S1 ) has been synthesized and characterized by FTIR, NMR, and MS analyses. S1 shows high selectivity and sensitivity toward F − ions among several tested anions (Cl − , Br − , I − , OAc − , NO 3 − , HSO 4 − , H 2 PO 4 − , CN − ) in CHCl 3 . Upon addition of F − ions, the maximum absorption band of S1 in CHCl 3 displayed a red shift from 581 to 588 nm. This shift was visually manifested as a color change from pink to blue. When excited at 550 nm, the fluorescent emission intensity of S1 at 608 nm was quenched to over 87% of its initial value. Both a Job's plot and 1 H NMR spectra analysis revealed a 1:1 stoichiometric relationship between S1 and the added F − ions. Moreover, we found that the absorption and fluorescence of the S1 –F − complex was reversible upon addition of HSO 4 − ions. Finally, by using F − and HSO 4 − ions as chemical inputs and the absorbance and fluorescence intensity as outputs, a complementary INHIBIT/IMPLICATION (INH/IMP) logic gate was constructed at the nanoscale level. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new colorimetric and turn-on fluorescent chemosensor (Se-1) was synthesized. [•] Se-1 shows remarkable color changes and fluorescence enhancement with Hg2+ or Cu2+. [•] The Hg2+-induced chromogenic process could be reversed by addition of EDTA or cysteine. [ABSTRACT FROM AUTHOR]

A chemosensor consisting of two terpyridines covalently linked to a dithienosilole unit ( 1 ) has been synthesized, and its optical and metal sensing properties have been investigated. Due to the metal–organic coordination function, 1 can bind with many transition metal ions and display different fluorescence responses that cause it to function as a “turn-off” fluorescent chemosensor. A significant bathochromic shift in the fluorescence spectra is observed in the presence of Zn 2+ . Meanwhile, the emission of 1 is weakened upon exposure to Ag + and Fe 2+ and completely quenched by Ni 2+ , Co 2+ , and Cu 2+ . Based on the observed results, several logic gates, such as XNOR, INHIBIT, and IMPLICATION, have been achieved by controlling the chemical inputs. [ABSTRACT FROM AUTHOR]

A novel near-infrared fluorescent chemosensor based on BODIPY ( Py-1 ) has been synthesized and characterized. Py-1 displays high selectivity and sensitivity for sensing Cu 2+ over other metal ions in acetonitrile. Upon addition of Cu 2+ ions, the maximum absorption band of Py-1 in CH 3 CN displays a red shift from 603 to 608 nm, which results in a visual color change from pink to blue. When Py-1 is excited at 600 nm in the presence of Cu 2+ , the fluorescent emission intensity of Py-1 at 617 nm is quenched over 86%. Notably, the complex of Py-1 –Cu 2+ can be restored with the introduction of EDTA or S 2− . Consequently, an IMPLICATION logic gate at molecular level operating in fluorescence mode with Cu 2+ and S 2− as chemical inputs can be constructed. Finally, based on the reversible and reproducible system, a nanoscale sequential memory unit displaying “Writing–Reading–Erasing–Reading” functions can be integrated. [ABSTRACT FROM AUTHOR]