Supramolecular modulation in photophysical features of berberine and its application towards ATP sensing

Entropy-Driven Inclusion of Natural Protoberberine Alkaloids in Sulfobutylether-β-Cyclodextrin

“…The experimental data in Figure S1 in the Supplementary Materials show that the association constant (K = (1.92 ± 0.10) × 10 4 M −1 ) remains unchanged within the limit of experimental errors in dilute B solution confirming 1:1 complexation stoichiometry. The K value obtained in the present study is considerably smaller than the quantity (2.67 × 10 5 M −1 ) reported for B incorporation in SBE 10 βCD, a host possessing 10 sulfobutylether groups [ 16 ]. This is in accord with the predicted decline in the binding strength of a cationic guest with the degree of substitution on βCD [ 9 ].…”

“…Berberine exhibited high affinity to β-CD possessing 10 sulfobutylether arms. The strong 1:1 association induced ~190-fold fluorescence intensity enhancement, which was quenched by ternary complex formation with Cd 2+ ion [ 16 ].…”

Aggregation assisted turn-on response of ANS dye towards protamine

“…44 Such aggregation reduces the polarity at the vicinity of dye molecules and affects the H-bonding of dye with bulk water molecules, resulting in a red shift in the peak absorption. 43,45 It should be noted that there is a nice crossover region (isosbestic points) at ∼380 nm, which clearly indicates the presence of dynamic equilibrium between the monomer and aggregated species in the solution. Thus, all these aforementioned results altogether support the interaction of ANS dye with protamine in the ground state.…”

“…1, the ground state absorption spectrum of ANS dye in the absence of protamine features a strong peak at ∼270 nm and a relatively weak peak at ∼356 nm corresponding to π → π* and n → π* transitions, respectively. 43 Gradual addition of protamine to the dye solution causes a substantial decrease in the absorption maxima at a shorter wavelength along with an increase in the absorbance of the tail at ∼405 nm. Furthermore, an appreciable red shift in the absorption peak is also observed.…”

A cationic detergent based dye supramolecular assembly as a unique turn-on probe for ATP quantification

“…Fluorescence-based detection techniques, on the other hand, have been found to offer all the aforementioned advantages in addition to their minimum sample requirement and non-destructive nature. 29,30 Till date various fluorescent probes have been used for the detection of ATP that can either recognise ATP directly or supramolecular assemblies of the probes taking part in the ATP recognition process. [29][30][31][32][33][34][35][36] In this study, a supramolecular assembly of dansylated gemcitabine derivative (GEM-DNS) and a cationic surfactant cetyl trimethyl ammonium bromide (CTAB) was used as a turn-on fluorescent probe for ATP detection.…”