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A multifunctional self-assembled dual-chemosensor DTS was synthesized and used for optical and microstructural based discrimination of Hg 2+ , CN − ions and Hg(CN) 2 ion-pair. The addition of Hg 2+ ions to the CH 3 CN solution of DTS promotes the ESIPT phenomena (emission peak at 458 nm red shifted to 510 nm; increase in absorption between 400 and 480 nm), followed by cyclization (guanylation) reaction with concomitant desulfurization (decrease of emission intensity at 510 nm and minor increase at 410 nm; increase and decrease in absorbance intensity at 270 and 325 nm, respectively). In contrast, CN − induced deprotonation in DTS results in simultaneous decrease in absorbance at 310 nm and increase in absorbance at 385 nm and 425–475 nm and fluorescence enhancement at λ em 452 nm. On the addition of Hg(CN) 2 ion pair, DTS shows apparent effect of both Hg 2+ and CN − ions. The mechanism of interaction of DTS with Hg 2+ , CN − and Hg(CN) 2 has been established by detailed 1 H NMR and ESI–MS studies. DTS in CH 3 CN shows flake like morphology which undergoes analyte induced self-assembly to form a bunch of nanorods with Hg 2+ ; segregated nanorods with curvy ends with CN − and spherical structures with Hg(CN) 2 ion pair. [ABSTRACT FROM AUTHOR]

Unimolecular system SBU shows multiple output responses on interaction with Cu 2+ /F − ions individually and simultaneously. The complexation of Cu 2+ with imine ( C N) and OH groups results in blue-shift from 332 to 303 nm and de-protonation of OH group with F − ions causes red-shift of the absorption maxima from 332 to 405 nm. The addition of F − to SBU∩Cu 2+ solution or addition of Cu 2+ to SBU∩F − solution shifts the absorption maxima from 303 to 374 nm or 405–303 nm, respectively. Similarly, the complexation of Cu 2+ ions, inhibits the ESIPT emission at 512 nm with concommitant release of emission at 425 nm, whereas F − results in quenching of emission at 512 nm up to 10 μM, followed by blue-shift to 425 nm at >10 μM F − ions. The addition of F − to SBU∩Cu 2+ solution causes quenching of emission at 512 and 425 nm, whereas addition of Cu 2+ to complex SBU∩F − solution revives the emission at 425 nm considerably. These multiple output response leads to elaboration of YES, NOT, NOR, INH, AND, XOR and XNOR logic gates and Half-adder, Half-subtractor, 2-to-4 decoder, 1:2 demultiplexer, Magnitude Comparator, complimentary OR/NOR circuit and molecular keypad lock logic circuits. [ABSTRACT FROM AUTHOR]

Graphical abstract Self-assembled fibre-to-disc fluorescent aggregates of coronene diimide were explored for tuning of their emission color, visualization of latent fingerprints (solution and powder dusting methods) and bio-labeling of HeLa cells. Highlights • Two novel coronene diimides have been synthesized. • Controlled transformation of fibre-to-disc-like aggregates alongside tuning of their emission color has been achieved. • Red fluorescent aggregates of CDI 3 show application in visualization of latent fingerprints. • For the first time CDI 3 were used in powder dusting method to visualize the latent fingerprints on porous surfaces. • CDI 3 was also explored for bio imaging of HeLa cells. Abstract Coronenediimide (CDI 3) forms long fibrillar nanostructure when dissolved in DMF. On addition of >70% water in DMF, CDI 3 undergo fibre-to-disc morphological transformation alongside onset of different emission colors in water-DMF binary mixtures. These self-assembled red emitting aggregates of CDI 3 applied for visualization of latent fingerprints using solution spray and powder dusting methods on porous and non-porous surfaces commonly found in home such as aluminium, stainless steel, glass, metal coins, compact discs (CDs), OHP films, ceramic tiles and paper sheets. In an attempt to explore the application of CDI 3 in the forensic cases, 2nd level of information was used for distinguishing different fingerprints from different subjects. These disc-like fluorescent red aggregates of CDI 3 were also used for staining of HeLa cells. [ABSTRACT FROM AUTHOR]

We report perylenediimide-benzimidazolium based fluorescent ‘turn-on’ probe BIM-PDI for selective detection of human serum albumin (HSA) and bovine serum albumin (BSA) proteins. In HEPES buffer (0.1% DMSO), BIM-PDI self-assembles into aggregates and shows absorption maxima at 500 nm and weak fluorescence centered at 577 nm. The addition of HSA or BSA (1 × 10 −9 –5 × 10 −8 M) to the solution of BIM-PDI results in decrease in the emission intensity at 577 nm. However, further increase in concentration of HSA/BSA results in appearance of new blue shifted emission band at 540 nm. The minimum detection limit for HSA/BSA is 3.01 × 10 −10 M at 577 nm and 4.2 × 10 −8 M at 540 nm. On addition of BSA to the solution of BIM-PDI , the size of the aggregates decreased from 100 to 250 nm to <10 nm assigned to microencapsulation driven disassembly of BIM-PDI aggregates responsible for ‘turn-on’ response in fluorescence spectrum. Site-selective experiments using warfarin and diazepam drugs show that BIM-PDI preferably binds at site-I of HSA/BSA proteins. In clinical application of BIM-PDI , we estimated HSA content in blood serum and urine samples. BIM-PDI showed potential application in serum albumin protein tracking and imaging. [ABSTRACT FROM AUTHOR]