Magnetic Graphitic Nanocapsules for Programmed DNA Fishing and Detection

Abstract

Graphene nanomaterials are typically used in biosensing applications, and they have been demonstrated as good fluorescence quenchers. While many conventional amplification platforms are available, developing new nanomaterials and establishing simple, enzyme-free and low-cost strategies for high sensitivity biosensing is still challenging. Therefore, in this work, a core-shell magnetic graphitic nanocapsule (MGN) material is synthesized and its capabilities for the detection of biomolecules are investigated. MGN combines the unique properties of graphene and magnetic particles into one simple and sensitive biosensing platform, which quenches around 98% of the dye fluorescence within minutes. Based on a programmed multipurpose DNA capturing and releasing strategy, the MGN sensing platform demonstrates an outstanding capacity to fish, enrich, and detect DNA. Target DNA molecules as low as 50 pM could be detected, which is 3-fold lower than the limit of detection commonly achieved by carbon nanotube and graphene-based fluorescent biosensors. Moreover, the MGN platform exhibits good sensing specificity against DNA mismatch tests. Overall, therefore, these magnetic graphitic nanocapsules demonstrate a promising tool for molecular disease diagnosis and biomedicine. This simple fishing and enrichment strategy may also be extended to other biological and environmental applications and systems.

In situ targeted MRI detection of Helicobacter pylori with stable magnetic graphitic nanocapsules

“…in 1 H-NMR and 3,215 cm −1 in FTIR also demonstrated the formation of an amide bond, indicating the successful synthesis of B-PEG molecules. The graphitic shell of the MGNs could quench the fluorescence of a proximal fluorophore through the fluorescence resonance energy transfer effect52. The fluorescence of the boronic acid group on B-PEG substantially decreased after interacting with the MGNs, indicating the successful functionalization of B-PEG on the surface of the MGNs (Fig.…”

Multifunctional carbon nanomaterial hybrids for magnetic manipulation and targeting

“…Numerous studies have reported the use of magnetic CNMs for magnetic separation and purification of low-abundant biomolecules, including proteins [53e56], antigens [57], phosphopeptides [58,59], and DNA, from complex biological samples [60].…”

Fabrication of GO/magnetic graphitic nanocapsule/TiO2 assemblies as efficient and recyclable photocatalysts

“…To increase photocatalytic recyclability in waste water, we herein assembled TiO 2 nanoparticles and magnetic graphitic nanocapsules (MGN) [25][26][27] onto a graphene oxide surface to fabricate a corrosion resistant, highly effective and stable GO/magnetic graphitic nanocapsule/TiO 2 photocatalyst system (GMG-TiO 2 , Scheme 1). TiO 2 and the MGNs are synthesized through the sol-gol and chemical vapor deposition method, respectively.…”