Synthetic Supramolecular Host for D‐(−)‐Ribose: Ratiometric Fluorescence Response via Multivalent Lectin‐Carbohydrate Interactions

Abstract

Easily synthesizable, carbazole-based organic nanoaggregates have been designed for selective detection of D-(À )-ribose at physiological pH. The addition of D-ribose results in a ratiometric change in fluorescence color from green to cyan (LOD: ~12 μM). The mechanistic studies indicate the presence of multipoint noncovalent interactions, such as hydrogen bonding and CH•••π interactions between D-ribose and acyl hydrazone and terminal pyridyl units of the probe molecule. However, such multipoint interactions dissociate the preformed self-assembled nanoclusters and induce change in optical response. The probe molecule was further exploited in analyzing D-ribose content in biological fluids (diluted human urine and blood serum) and oral supplements. The small standard deviation values (2-3.8 %) with nearly quantitative recovery (93.5-105.5 %) indicate the high accuracy of the presented method. Further, low-cost portable device based coated paper strips were designed for 'on-location' rapid, detection of Dribose even at remote locations.

Differential response for multiple ions: a smart probe to construct optically tunable molecular logic systems

“…Interaction of rhodamine-based sensors with metal ions can occur either through ion-induced spirolactam ring opening or ion catalyzed hydrolysis reaction. 26 The EDTA-mediated recovery experiment with both Hg 2+ and Cu 2+ clearly indicated that the observed optical changes were due to the reversible spirolactam ring opening, and not due to ion-induced hydrolysis (Fig. 3b).…”

Dual-Mode Multiple Ion Sensing via Analyte-Specific Modulation of Keto–Enol Tautomerization of an ESIPT Active Pyrene Derivative: Experimental Findings and Computational Rationalization

“…Now, we have constructed binary logic functions with Zn 2+ and Cu 2+ as dual stimulating inputs and absorbance and fluorescence as outputs (Figure 6). 75,76 Upon the addition of Zn 2+ ions (Input-1), a new fluorescence band appeared at 527 nm, attributed to a typical exciplex formation as described above. On the contrary, in the presence of Cu 2+ ions (Input-2), the emission band at 565 nm was quenched, probably due to the combined effect of PET and intramolecular charge transfer.…”

“…Now, we have constructed binary logic functions with Zn 2+ and Cu 2+ as dual stimulating inputs and absorbance and fluorescence as outputs (Figure ). , …”

Polarity-Independent Temperature-Induced Reversible Fluorescence Switching of Organic Nanoparticles: Application to Intracellular Temperature Imaging

“…Subsequently, we explored the application of compound 1 for the determination of intracellular temperature using HeLa cells as a model system. , For this, the first cytotoxicity of the compound was assayed (Figure b). More than 75% were found to be viable even when the cells were treated with ∼50 μM of compound 1 for more than 48 h. This observation indicates that the fluorogenic probe is biocompatible and therefore can be utilized for the determination of temperature inside a living mammalian cell.…”