Insights into the Strong Emission Enhancement of Molecular Rotor Thioflavin T in Aqueous Cellulose Nanocrystal Dispersion: White Light Generation in Protein and Micellar Media

Thioflavin t (THT) is a well-known molecular rotor extensivelyused to detect amyloid-like structures. But THT shows very weak emissionin water. In this article, we have found that THT shows very strongemission in the presence of cellulose nanocrystals (CNCs). Steady-stateand time-resolved emission techniques have been used to study thestrong emission of THT in aqueous CNC dispersion. The time-resolvedstudy showed that in the presence of CNCs, the lifetime increasedby similar to 1500 fold compared to pure water (<1 ps). To know thenature of interaction and also the reason for this increase in emissionzeta potential, stimuli-dependent and temperature-dependent studieshave been carried out. These studies proposed that electrostatic interactionis the main factor for this binding of THT with CNCs. Further, theaddition of another anionic lipophilic dye, merocyanine 540 (MC540),with CNCs-THT in both BSA protein (CIE: 0.33, 0.32) and TX-100micellar (4.5 mM) (CIE: 0.32, 0.30) solutions produced excellent whitelight emission. Lifetime decay and absorption studies proposed a possiblefluorescence resonance energy transfer mechanism in this generationof white light emission.

Automated summary

In this study, it was discovered that THT exhibits strong emission in the presence of cellulose nanocrystals (CNCs). The emission properties of THT in aqueous CNC dispersion were investigated using steady-state and time-resolved emission techniques. The results showed that the lifetime of THT increased by approximately 1500 fold in the presence of CNCs compared to pure water (<1 ps). Stimuli-dependent and temperature-dependent studies suggested that electrostatic interaction is the main factor for the binding of THT with CNCs.