Magnetic guanidyl–functionalized covalent organic framework composite: a platform for specific capture and isolation of phosphopeptides and exosomes

In situ grown magnetic COF@MOF with a phosphoserine anchor for in-depth N-glycopeptide analysis in serum

“…The structures of Fe 3 O 4 @COF@MOF-PS were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). First, in the XRD spectrum of Fe 3 O 4 @COF@MOF-PS, it could be seen that the seven crystalline planes of (111), (220), (311), (400), (422), (511), and (440) belong to Fe 3 O 4 , 28 and the crystalline plane of (022) 31 belongs to the Zr-MOF. A strong peak at 0.75° indicated that the COF had good crystallinity (Fig.…”

“…† 2.2 Synthesis of the Fe 3 O 4 @COF@MOF-PS composite Firstly, the synthesis of Fe 3 O 4 refers to our group's previous work, and the specific information can be found in the ESI. † 28 Secondly, 100 mg of Fe 3 O 4 and 74.76 mg of 2,5-dihydroxyterephthalaldehyde (Dta) were dispersed in 37.5 mL of acetonitrile (ACN), then 105.4 mg of 1,3,5-tris (4-aminophenyl) benzene (TAPB) and anhydrous sodium acetate (HAc) (5.25 mL, 12 M) were added, and then stirred for 24 h to obtain Fe 3 O 4 @COF-OH. After collecting with a magnet, Fe 3 O 4 @COF-OH was washed with anhydrous tetrahydrofuran (THF) and ethanol, and then dried.…”

Combination of click chemistry and Schiff base reaction: Post‐synthesis of covalent organic frameworks as an immobilized metal ion affinity chromatography platform for efficient capture of global phosphopeptides in serum with chronic obstructive pulmonary disease

“…The absorption peak at 1677 cm −1 on the spectra of DVA was ascribed to the -C = O [26]. The peak at 1618 cm −1 was attributed to -C = N vibration [30], indicating the successful occurrence of the aldehyde-amine condensation reaction. The spectra of COF@GSH@THBA showed new peaks appearing at 1445 and 1724 cm −1 belonging to the vibration of -OH and -COOH [31], respectively, suggesting the good modification on the COF layer of THBA and GSH.…”

Post-synthesis of a titanium-rich magnetic COF nanocomposite with flexible branched polymers for efficient enrichment of phosphopeptides from human saliva and serum

“…13 Among these approaches, the IMAC enrichment strategy is an effective and widely employed method for capturing phosphopeptides via metal ion chelation and electrostatic interaction. 14 At present, the frame materials based on the IMAC phosphopeptide enrichment strategy primarily consist of metalorganic frameworks (MOFs), 15,16 silica materials, [17][18][19] carbon materials, 20,21 and covalent organic frameworks (COFs), 22,23 which greatly promote the development of phosphoproteomics. COFs have significant advantages in separating and enriching phosphopeptides through post-synthesis modification because of their excellent thermochemical stability, large specific surface area and porosity, permanent pore structure, low skeleton density, and diverse synthesis strategies.…”

“…22,[24][25][26] Magnetic COFs, which combine the benefits of magnetic responsiveness, have recently been considered an ideal absorbent for efficient phosphopeptide enrichment. 23,[27][28][29][30] Few reports of phosphopeptide enrichment materials of magnetic COFs based on the IMAC enrichment strategy have been published. 25,31,32 Simultaneously, enhancing the metal binding sites on the surface of magnetic COF materials is critical for efficient phosphopeptide enrichment, which is both a challenge and a worthwhile direction to explore.…”