fig10

Figure 10. (A) Schematic illustration of synthesis of TpPa-2-Ti⁴⁺ through condensation and coordination with chemical structure of TpPa-2 and chemical structure of TpPa-2-Ti⁴⁺; (B) Representation of the strategy for preparing Zr⁴⁺-immobilized magnetic COFs through sequential post-synthetic modifications; (C) Schematic representation of preparation of TpTGCl CONs, and enrichment procedure of phosphopeptides with TpTGCl CONs; (D) Powder XRD patterns of simulated and as-synthesized TpTGCl CONs; (E) TEM image of TpTGCl CONs; (F) AFM image and height profile of TpTGCl CONs. MALDI-TOF MS of non-fat milk tryptic digest; Direct analysis (G), after enrichment by TpTGCl CONs in buffer A (H). MALDI-TOF MS of human saliva (5 μL); Direct analysis (I), after enrichment by TpTGCl CONs in buffer A (J) (“s” in blue indicates mono-phosphopeptide, “m” in red indicates multi-phosphopeptide. For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article); (K) Distribution proportions of mono- and multi-phosphopeptides identified from rat liver protein digest by TpTGCl CONs in buffer A and buffer B, respectively. And distribution proportions of the integrated phosphorylation sites identified from rat liver protein digest by TpTGCl CONs in buffer A and buffer B; GO analysis by DAVID for the identified phosphoproteins from rat liver protein digest, including biological process (L), molecular function (M). (A) is reprinted with permission from Ref.^[133], Copyright © 2017 by Elsevier. (B) is reproduced with permission from Ref.^[134], Copyright © 2021 by American Chemical Society. (C-M) are reproduced with permission from Ref.^[135], Copyright © 2021 by Elsevier. Tp: 1,3,5-Triformylphloroglucinol; Pa-2: 2,5-dimethyl-1,4-benzenediamine; COFs: covalent organic frameworks; TGCl: triaminoguanidinium chloride; CONs: covalent organic nanosheets; XRD: X-ray diffraction; TEM: transmission electron microscopy; AFM: atomic force microscopy; MALDI-TOF MS: matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; GO: Gene Ontology; DAVID: database for annotation, visualization, and integrated discovery.