The quenching effect of silver nanoparticles on 2-amino-3-bromo-1, 4-naphthoquinone using fluorescence spectroscopy

A Sensitive, Simple and Direct Determination of Pantoprazole Based on a “Turn off-on” Fluorescence Nanosensor by Using Terbium-1,10-phenanthroline-silver Nanoparticles

“…If there is no overlap between the emission spectrum of the fluorophore and the absorption spectrum of MNPs, the dominant mechanism will be electron transfer. [54][55][56][57] In the present study, the fluorescence emission intensity of the Tb(III)-phen complex was strongly quenched in the presence of AgNPs (Ksv = 2.08 × 10 11 M -1 ). Since there is a good overlap between the emission and absorption spectra of the donor and acceptor and the interaction between them is strong, and the fluorescent probe is placed in the vicinity of a AgNPs, as well as the size of AgNPs used in the present study was larger than 5.0 nm, therefore, the observed fluorescence quenching of the Tb(III)-phen complex in the presence of AgNPs is probably due to energy transfer between the Tb(III)-phen complex and AgNPs.…”

“…This result indicated that Tb(III)-phen molecules were released from the surfaces of AgNPs due to the displacement of Tb(III)-phen molecules with PAN and the binding of PAN molecules onto the surface of the AgNPs instead of Tb(III)-phen. 26,31,33,36,39,[54][55][56][57] It has been reported that the MNPs (which are 12 -100 nm in diameter) can bind to fluorophore molecules and quench or enhance their fluorescence intensity without changing their structure. The intensity of the quenching or enhancement is strongly related to the size and shape of the MNPs.…”

A rapid, simple and ultrasensitive spectrofluorimetric method for the direct detection of metformin in real samples based on a nanoquenching approach

“…The size and shape of metal nanoparticles are the two main factors that could affect the strength of the fluorescence quenching or enhancement. [ 66,67 ] It is well known that the electron and energy transfer processes are the two main mechanisms for fluorescence quenching of excited fluorophore molecules on metal nanoparticle surfaces. For particle sizes of < 5.0 nm and > 5.0 nm, the electron transfer mechanism and energy transfer are predominant, respectively.…”

“…So, considering that interaction between the Tb(III)–phen complex and AgNPs was strong (K sv = 3.5 × 10 10 M −1 ) and there was a good overlap between emission and absorption spectra, plus the size of AgNPs used here was larger than 5.0 nm, therefore the fluorescence quenching of the Tb–phen complex in the presence of AgNPs was probably due to energy transfer between them (from the Tb–phen complex to AgNPs). [ 66–68 ]…”