Fluorescence quenching studies of CTAB stabilized perylene nanoparticles for the determination of Cr(vi) from environmental samples: spectroscopic approach

Abstract

CTAB-PNPs are bound to dichromate ion by electrostatic interaction to form stable non-fluorescent micellar complex which is responsible for the ‘FL quenching’ of CTAB-PNPs.

N-methyl isatin nanoparticles as a novel probe for selective detection of Cd2+ ion in aqueous medium based on chelation enhanced fluorescence and application to environmental sample

“…N-MINPs were prepared by a reprecipitation method [12,28,29] in aqueous medium. A 2 mL, 1 × 10 −5 M solution of N-MI in acetone was injected directly into 50 mL water and stirred for 60 min, followed by ultrasonication for 10 min.…”

“…The enhanced emission arising from FONs have been widely employed to sense metal ions and methods reported in the literature are of high sensitivity, special selectivity and good stability [11,12]. The past few years have witnessed a number of sensory reports on the design and synthesis of functionalized FONs for the detection of metal ions [13][14][15][16][17].…”

“…FONs are prepared by using different methods, viz. Emulsification evaporation, emulsification diffusion [18], laser ablation [19,20] and reprecipitation method [12]. The reprecipitation method for preparation of fluorescent nanoparticles demands functionalized fluorescent small organic molecule having more hydrophobicity by which it could nucleates and undergoes aggregation in aqueous medium.…”

Selective sensing of Fe2+ ions in aqueous solution based on fluorescence quenching of SDS capped rubrene nanoparticles: application in pharmaceutical formulation

“…6 Here in, SDS capped RUBNPs exhibited J-type aggregates or head-to-tail structure that usually showed fluorescence with an intensity that fairly often exceeded that of the monomer rubrene solution in THF. According to the exciton theory of Kasha et al [4][5][6] in J aggregates, only transitions to the low energy states of the exciton band are allowed and, as a consequence, J-aggregates are characterized by a high fluorescence quantum yield. Fluorescence spectroscopy suggested that the SDS-RUBNPs existed in equilibrium with molecular rubrene in solution as its characteristic bands are not appeared in fluorescence spectrum of nano dispersion.…”

“…Among them, polycyclic aromatic hydrocarbons, such as pyrene, anthracene andperylene are frequently employed for sensor applications. [4][5][6] The investigation of nanoparticles and microcrystals of such organic molecular materials is currently a rapidly growing field.…”