FITC functionalized magnetic core–shell Fe3O4/Ag hybrid nanoparticle for selective determination of molecular biothiols

Abstract

a b s t r a c tA sensing strategy for chromogenic detection of molecular biothiols has been proposed based on fluorescein isothiocyanate (FITC) functionalized magnetic core-shell Fe 3 O 4 /Ag hybrid nanoparticles. Ag coated magnetic Fe 3 O 4 nanoparticles were initially synthetized. FITC was subsequently conjugated on the surface of core-shell nanoparticles by Ag-SCN linkage and then the fluorescence of FITC was quenched. Upon addition of molecular biothiols, since the Ag S bond is stronger than Ag-SCN, a place-displacement between thiols and FITC would occur and thereby the fluorescence of FITC would recover. Thus, a fluorescence "off-on" probe was attained by virtue of biothiols, so after magnetic separation, the fluorescence signal change of FITC in clear solution could be employed for quantitative determination of typical molecular biothiols such as glutathione (GSH) and cysteine (Cys). High sensitivity was obtained with the detection limits of 10 nM and 20 nM for GSH and Cys, respectively. As well as, the assay strategy presented excellent selectivity toward molecular biothiols against other amino acids. Furthermore, confocal imaging was achieved in living cells, indicating that this fluorescent probe is potentially applicable for imaging molecular thiols in biological systems.

Enhancing Anti-Tumor Efficacy of Doxorubicin by Non-Covalent Conjugation to Gold Nanoparticles – In Vitro Studies on Feline Fibrosarcoma Cell Lines

“…FT-IR spectra of Au-GSH shows characteristic GSH absorption broad bands around 1660 cm-1 coming from NH bending and C = O stretching modes, while no signal at 1570 cm−1 (C = S) is observed confirming the absence of free GSH in the sample. [ 46 , 47 ] FT-IR analysis of Au-GSH-Dox revealed additional bands, e.g. signals at 1280 (C-O-C stretching), 1404 (C-C stretching) and 1612 cm-1 (NH bending) due to Dox conjugation.…”

Preparation of a fluorescent silver nanoprism–dye complex for detection of hydrogen peroxide in milk

“…Here, Ag nanoprisms were prepared under the condition without polyvinylpyrrolidone (PVP) macromeluecules 18 , which facilitates the absorption of BSA onto the surface of Ag nanoprisms and the labeling of FITC on the Ag nanoprisms surface. The surface plasmon resonance (SPR) absorption of the prepared Ag nanoprisms was at 750 nm (Fig 1) and the products are mainly triangular nanoparticles (Fig 2).…”

“…For example, uorescein isothiocyanate (FITC) functionalized magnetic coreshell Fe 3 O 4 /Ag hybrid nanoparticles were utilized to detect biothiols sensitively. 18 A novel detection method for copper ions was designed based on uorescent FITC functionalized gold nanoparticles (FITC-Au NPs). 19 In this communication, we prepared a Ag nanoprism-dye complex (FDSNP) which was applied to detect H 2 O 2 in milk.…”

Use of metal nanoparticles for preconcentration and analysis of biological thiols

“…Except for AuNPs and AgNPs, other types of NPs were utilized for fluorescence detection; some of them are listed later. Magnetic Fe 3 O 4 @Ag NPs functionalized with fluorescein isothiocyanate (FITC) were used for the determination of biothiols in the work of Chen et al [64]. As the Ag-S bond with biothiols is stronger than Ag-SCN linkage of FITC, FITC is released, and its fluorescence is measured.…”

“…Chen et al. [64] fabricated Fe 3 O 4 @Ag core–shell NPs functionalized with fluorescein isothiocyanate for fluorescence detection of thiol compounds. The bimetallic alloy NPs are synthesized by a simultaneous coprecipitation of appropriate precursors.…”