Fabrication of Magnetic Upconversion Nanohybrid for Luminescent Resonance Energy Transfer-Based Detection of Glutathione.

This study introduces the facile fabrication of a bimodal nanohybrid for the luminescent ON/OFF detection of glutathione. The proposed nanosensor consists of magnetic (Fe3O4) and upconversion nanoparticles (UCP) co-encapsulated in a silica matrix, and decorated with gold nanoparticle (AuNP) as a luminescent quencher. The detection mechanism is based on the Luminescent Resonance Energy Transfer (LRET) between the donor (UCP) and the acceptor (AuNP) with the help of a disulfide bond as a bridging element. In the presence of glutathione, the disulfide bridges between AuNPs and Fe3O4/UCP@SiO2 was cleaved and the amount of glutathione could be traced by the restored luminescence (ON state) of the nanohybrids after magnetic separation.