Walls Of Silica Research Articles

Enzymatic Reaction Enhanced Diffusion Accelerates Cargo Transport through Micro/Nano-Channels.

Energy conversion and transfer of enzyme-catalyzed reactions at molecular level are an interesting and challenging scientific topic that helps understanding biological processes in nature. In this study, it is demonstrated that enzyme-catalyzed reactions can enhance diffusion of surrounding molecules and thus accelerate cargo transport within 1D micro/nanochannels. Specifically, urease is immobilized on the inner walls of silica micro/nano-tubes to construct bio-catalytically active micro/nanochannels. The catalytic reaction inside the channels drives a variety of cargoes, including small dye molecules, polymers, and rigid nanoparticles (e.g., quantum dots, QDs), to pass through these micro/nanochannels much faster than they will by free diffusion. The enhanced diffusion of molecular species inside the channels is validated by direct observation of the Brownian motion of tracer particles, and further confirmed by significantly enhanced Raman intensity of reporter molecules. Finite element and Brownian dynamics simulations provide a theoretical understanding of these experimental observations. Furthermore, the effect of the channels' size on the diffusion enhancement is examined. The acceleration effect of the cargo transport through these enzymatically active micro/nanochannels can be turned on or off via chemical activators or inhibitors. This study provides valuable insights on the design of biomimetic channels capable of controlled and efficient transmembrane transport.

Dihydropyrano quinoline derivatives functionalized nanoporous silica as novel fluorescence sensor for Fe3+ in aqueous solutions(aq)

A novel nanoporous silica-based fluorescence sensor with high selectivity and sensitivity was successfully prepared via grafting of 3-isocyanatopropyltriethoxysilane and dihydropyrano [3, 2-c] quinoline derivatives (DPQ) onto the pore walls of mesoporous silica. The attachment of fluorophore groups onto the surface of the SBA-15 was approved via TGA and FT‐IR spectroscopy. TGA analysis indicates a large weight loss about 49%, which is attributed to the binding of a large number of organic groups on the pores surface, which functional groups appeared in the FT-IR spectra. Structural characterization techniques have proved the type IV for N2 adsorption-desorption isotherm, which revealed the preservation of the mesoporous structure. Also, low-angle XRD, FESEM and TEM analyses demonstrate the formation of ordered and well-defined 2D hexagonal mesoporous structure (space group p6mm). Whereas, Fe3+ ions caused discernible fluorescence quenching of the fluorescence sensor, the other cations used did not significantly changed fluorescence emission of SBA-Si-DPQ. The fluorescence quenching of the sensor is attributed to the paramagnetic properties of Fe3+ ions that appear by complex formation between the urea group of the probe and Fe3+ ions. It is noteworthy that, the excitation at 310 nm caused an emission with a maximum at 478 nm wavelength. By the increasing concentration of the analytes, the emission intensity was decreased dramatically and good linearity observed between analytes concentrations and the fluorescence intensity quenching of the sensor. The measured detection limits for Fe3+ ions was 2.0 × 10−6 M.

Synthesis of bifunctional groups-integrated mesoporous silica hybrid adsorbent for simultaneous removal of Hg2+ and Cu2+ ions from aqueous solution

A mesoporous organosilica hybrid integrated with disulfide and amine groups was synthesized in a sol-gel co-condensation method using Pluronic P123 as structural directing surfactant. In the initial silane mixture, the organic functional groups content of disulfide and amine groups along with tetraethyl orthosilicate incorporated into the pore walls of mesoporous silica is approximately 30 mol/g (BDSTES: AAPTES is 15:15 mol/g). The surface area, pore volume and pore size of the prepared disulfide bridged and amine groups integrated mesoporous silica hybrid adsorbent (MSHA@SS-NH2) materials are approximately 462 m2/g, 0.58 cm3/g, and 2.6 nm, respectively. The MSHA@SS-NH2 adsorbent materials demonstrated that adsorption equilibrium could be achieved in 30 min and the adsorbed amount of Hg2+ and Cu2+ ions calculated to be about 166 mg/g and 153 mg/g, respectively, with the ∼ 90% of Hg2+ ions and ∼ 84% of Cu2+ ions removal capacity from the mixture of initial metal ions solutions (100 mg/L). By washing with 0.1 M HCl solution and regenerating with aqueous ammonia (3%) solution, the MSHA@SS-NH2 adsorbent demonstrated recyclable and reusable ability up to 5 times. As a result, the MSHA@SS-NH2 material developed could be used as an effective adsorbent for the simultaneous removal of Hg2+ and Cu2+ ions from wastewater.

Highly selective fluorescence detection of Cu2+ based on Schiff base functionalized periodic mesoporous organosilicas.

A novel copper ion sensing periodic mesoporous organosilica (SCN-PMO) was obtained by incorporating a Schiff base-based fluorescent receptor into the pore walls of mesoporous silica, which exhibited a well ordered mesoporous structure and excellent optical properties demonstrated by various characterization results. SCN-PMO possessed high selectivity and sensitivity towards Cu2+ based on its specific fluorescence response. The detection limit of SCN-PMO could be as low as 6.7 × 10-7 M. Due to protection of the silica network, SCN chromophores in PMOs exhibited higher photostability and the resulting material possessed great repeatability. Additionally, the fluorescence changes of SCN-PMO towards copper ions in vivo (zebrafish) showed that SCN-PMO has potential application as a nanoprobe in biological fields.

Preparation and Evaluation of Precipitated Silica for CO2 Removal

In gas separation and purification, adsorption using solid sorbents is very well known as an effective technology for removing acid gases. There are many applications to this technology where grafting functional groups of amines into the pore walls of silica can create a distinct adsorbent type. With this manipulation adsorbents operating conditions, regeneration, selectivity, and stability maybe controlled for a particular application such as the food industry, pharmaceuticals, textile industry, manufacturing, and shown interest in greenhouse gases mitigation. CO2 adsorption using precipitated silica supported amine is an attractive method for carbon capture technologies due to its high loading capacity, regeneration potential and low cost. H2S removal using silica has shown high loading as demonstrated by (Vaewdaow Jaiboon et al., 2014) at around 50-60wt% with an Si-TRI grafted silica [1]. Simultaneous adsorption with silica has not been extensively studied due to greater modification to the experimental setup which involves using sequential sorption and double stage bed reactors with varying feed temperatures for each species as CO2 generally takes longer to adsorb compared to H2S adding to the complexity of the dual adsorption mechanism. The purpose of this study is to synthesize precipitated silica from sodium silicate using CO2 as an acidizing agent and then impregnate polyethyleneimine (PEI) to produce CO2 adsorbent experimentally. The novel silica loading and regeneration potential will be evaluated with CO2. The adsorbent with various PEI contents from 30 to 65 wt% was prepared by a wet impregnation method. The surface area, pore volume and pore size were analysed by a nitrogen adsorption/desorption method. A scanning electron microscope was used to study the structure of the adsorbent, and a Thermogravimetric analysis (TGA) was performed using a Thermogravimetric analyser (SDT Q600). Precipitated silica having surface area of 117.9 m2/ and pore volume of 1.52 cm3/g was synthesized and used for PEI impregnation. The CO2 adsorption performance was examined using a flow Micro Reaction Calorimeter (URC) by flowing pure CO2 into analysis cell under isothermal condition. CO2 adsorption experiments will be conducted at different adsorption and regeneration temperatures to determine optimum operation temperature for CO2 capture. Preliminary results show an increase in mass of CO2 per gram of adsorbent from 89.8 to 180.04 mg/g as PEI impregnated contents increasing from 30 -60wt%, respectively. Further tests have been carried at various temperatures ranging from 60-90°C and a general increase in loading capacity was observed. When the sample was regenerated at 60°C the adsorption capacity decreased slightly for lower PEI wt% but increased higher than the first trial for higher PEI wt%. in general, with PEI 65wt% the loading of the amine dropped significantly. The outcome of this research will help strengthen the understanding of precipitated silica subjected to CO2 loading and the translation of the experimental model to a simulation model used to mimic a full-scale adsorption plant. The affinity towards CO2 will aid in the global research endeavour to study different morphologies and their optimum application space.

Biological Evaluation of Black Chokeberry Extract Free and Embedded in Two Mesoporous Silica-Type Matrices.

Black chokeberry fruits possess a wide range of biological activities, among which the most important that are frequently mentioned in the literature are their antioxidant, anti-inflammatory, anti-proliferative, and antimicrobial properties. The present paper reports, for the first time, the encapsulation of the ethanolic extract of Aronia melanocarpa L. fruits into two mesoporous silica-type matrices (i.e., pristine MCM-41 and MCM-41 silica decorated with zinc oxide nanoparticles). The aim of this work was to evaluate the antiradicalic capacity, the antimicrobial potential, and the effects on the cell viability on a cancer cell line (i.e., A375 human melanoma cell line) versus normal cells (i.e., HaCaT human keratinocytes) of black chokeberry extract loaded on silica-type matrices in comparison to that of the extract alone. The ethanolic polyphenolic extract obtained by conventional extraction was characterized by high-performance liquid chromatography with a photodiode array detector (HPLC–PDA) and spectrophotometric methods. The extract was found to contain high amounts of polyphenols and flavonoids, as well as good radical scavenging activity. The extract-loaded materials were investigated by Fourier transform infrared spectroscopy, N2 adsorption–desorption isotherms, thermal analysis, and radical scavenger activity on solid samples. The black chokeberry extract, both free and loaded onto mesoporous silica-type matrices, exhibited a significant antioxidant capacity. Antibacterial activity was recorded only for Gram-positive bacteria, with a more potent antibacterial effect being observed for the extract loaded onto the ZnO-modified MCM-41 silica-type support than for the free extract, probably due to the synergistic effect of the ZnO nanoparticles that decorate the pore walls of silica. The cellular viability test (i.e., MTT assay) showed dose- and time-dependent activity regarding the melanoma cell line. The healthy cells were less affected than the cancer cells, with all tested samples showing good cytocompatibility at doses of up to 100 µg/mL. Improved in vitro antiproliferative and antimigratory (i.e., scratch assay) potential was demonstrated through the loading of black chokeberry extract into mesoporous silica-type matrices, and the screened samples exhibited low selectivity against the tested non-tumor cell line. Based on presented results, one can conclude that mesoporous silica-type matrices are good hosts for black chokeberry extract, increasing its antioxidant, antibacterial (on the screened strains), and in vitro antitumor (on the screened cell line) properties.

Interconnected 3D Framework of CeO2 with High Oxygen Storage Capacity: High-Resolution Scanning Electron Microscopic Observation

CeO2 nanocasting in a mesoporous hard template provides a three-dimensionally (3D) interconnected skeleton framework consisting of CeO2 nanoparticles with particles smaller than 7 nm. Low-voltage high-resolution scanning electron microscopy with Ar-ion-beam cross-sectional polishing revealed numerous CeO2 (∼250 nm) clusters distributed in the SBA-15 mesochannels. Each CeO2 framework consists of CeO2 primary nanocrystals that are mutually and coherently connected. The mesochannel walls of the mesoporous silica might confine the growth of the CeO2 nanocrystals, resulting in a high oxygen storage capacity of the material. A series of cross-sectional images obtained by using damage-free Ar-ion-beam polishing revealed the mechanism of pore filling and CeO2 structuring process: that from the nucleation and growth of the CeO2 in the mesopores to the self-organization of nanocrystals that form multiple nanowires along the mesochannels. Furthermore, self-organized nanowires were arranged periodically and were mutually connected finally to form a negative replica of the ordered mesoporous SBA-15 silica.

Palladium oxide nanoparticles intercalated mesoporous silica for solvent free acceptorless dehydrogenation reactions of alcohols

Abstract Aggregation-free well-dispersed palladium oxide nanoparticles intercalated into the walls of mesoporous silica (PdOMS) were prepared by using thioether groups during the sol-gel preparation of mesoporous silica. The PdOMS material was characterized by N2 adsorption-desorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and UV–Vis spectroscopy. The material retains mesoporous structure with narrow pore size distribution with an average pore diameter of 6.8 nm and possesses high surface area of 683 m2g–1. The PdOMS catalyst was employed as an efficient heterogeneous catalyst in the acceptor- and oxidant-free dehydrogenation of neat alcohols to corresponding carbonyl compounds in very good to excellent yields (72–95%) at 80 °C under inert atmosphere. The catalytic efficacy of PdOMS has also been evaluated for the acceptorless dehydrogenative coupling reactions of alcohols with o-diamino benzene and o-amino phenol to yield azole-based heterocycles. The stability of PdOMS was assessed by investigating its recyclability and reusability in the dehydrogenation of neat alcohol for up to five cycles.

Palladium Intercalated into the Walls of Mesoporous Silica as Robust and Regenerable Catalysts for Hydrodeoxygenation of Phenolic Compounds.

Nanostructured noble-metal catalysts traditionally suffer from sintering under high operating temperatures, leading to durability issues and process limitations. The encapsulation of nanostructured catalysts to prevent loss of activity through thermal sintering, while maintaining accessibility of active sites, remains a great challenge in the catalysis community. Here, we report a robust and regenerable palladium-based catalyst, wherein palladium particles are intercalated into the three-dimensional framework of SBA-15-type mesoporous silica. The encapsulated Pd active sites remain catalytically active as demonstrated in high-temperature/pressure phenol hydrodeoxygenation reactions. The confinement of Pd particles in the walls of SBA-15 prevents particle sintering at high temperatures. Moreover, a partially deactivated catalyst containing intercalated particles is regenerated almost completely even after several reaction cycles. In contrast, Pd particles, which are not encapsulated within the SBA-15 framework, sinter and do not recover prior activity after a regeneration procedure.

Synthesis and characterization of mesoporous Pd(II) organometal nanoplatelet catalyst for copper-free Sonogashira reaction in water

Periodic mesoporous organopalladium(II)-bridged silica with platelet morphology (Pd(II)-PMO-P) was synthesized by the co-condensation of TEOS and Pd[PPh2(CH2)2Si(OC2H5)3]2Cl2 using P123 as structure-directing agent. The as-made Pd(II)-PMO-P samples were characterized with XRD, BET, ICP, SEM, TEM, solid NMR, XPS, as well as FT-IR. It was found that these products were composed of platelets (300–400 nm) with short and straight mesoporous channels (100–200 nm). Organopalladium (II) was integrally incorporated into the walls of silica. Compared to the organopalladium(II)-bridged PMO with irregular pore structure, Pd(II)-PMO-P catalyst exhibited high catalytic efficiency in the water-medium Sonogashira reaction because its short pore channels and nano-sized structures could accelerate the diffusion and adsorption of reactant molecules. Furthermore, the heterogeneous catalyst could be reused several times without significant loss of activity, which efficiently decreases the cost as well as the pollution in order to meet the criteria of green chemistry.

Zero-valent iron particles embedded on the mesoporous silica–carbon for chromium (VI) removal from aqueous solution

Nanoscale zero-valent iron (nZVI) particles were embedded on the walls of mesoporous silica–carbon (MSC) under the conditions of high-temperature carbonization and reduction and used to remove chromium (VI) from aqueous solution. The structure and textural properties of nZVI–MSC were characterized by the powder X-ray diffraction, transmission electron microscopy and N2 adsorption and desorption. The results show that nZVI–MSC has highly ordered mesoporous structure and large surface area, indistinguishable with that of MSC. Compared with the support MSC and iron particles supported on the activated carbon (nZVI/AC), nZVI–MSC exhibited much higher Cr(VI) removal efficiency with about 98 %. The removal process obeys a pseudo first-order model. Such excellent performance of nZVI–MSC could be ascribed to the large surface and iron particles embedded on the walls of the MSC, forming an intimate contact with the MSC. It is proposed that this feature might create certain micro-electrode on the interface of iron particles and MSC, which prevented the formation of metal oxide on the surface and provided fresh Fe surface for Cr(VI) removal.

Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica.

As a promising catalytically active nano reactor, gold nanoparticles intercalated in mesoporous silica (GMS) were successfully synthesized and properties of the materials were investigated. We used a one pot sol-gel approach to intercalate gold nano particles in the walls of mesoporous silica. To start with the synthesis, P123 was used as template to form micelles. Then TESPTS was used as a surface modification agent to intercalate gold nano particles. Following this process, TEOS was added in as a silica source which underwent a polymerization process in acid environment. After hydrothermal processing and calcination, the final product was acquired. Several techniques were utilized to characterize the porosity, morphology and structure of the gold intercalated mesoporous silica. The results showed a stable structure of mesoporous silica after gold intercalation. Through the oxidation of benzyl alcohol as a benchmark reaction, the GMS materials showed high selectivity and recyclability.

Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica

Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica

Synthesis of mesoporous carbons using silica templates impregnated with mineral acids

The pore walls of SBA-15, SBA-16 and KIT-6 mesoporous silica were acidified via the impregnation of phosphoric acid or sulfuric acid prior to their use as a template for mesoporous carbon synthesis with furfuryl alcohol. The effect of acid functionalization on carbon synthesis was investigated using X-ray powder diffraction, N2 adsorption, transmission electron microscopy, and solid-state 13C and 31P NMR spectroscopy. The results indicated that a significant portion of the impregnated mineral acid formed an ester with the surface silanol group. Therefore, the impregnated acid could lead to the selective formation of carbon frameworks inside the template pores, preventing external carbon deposition even when furfuryl alcohol was used excessively. The mineral acid impregnation yielded highly faithful carbon replicas of the mesoporous silica.

A rational strategy for preparing Cu–ZnO/H-ZSM-5 hybrid catalysts with enhanced stability during the one-step conversion of syngas to dimethyl ether (DME)

In this work, an original approach for preparing Cu–ZnO+H-ZSM-5 (Si/Al=15, denoted as Z5) hybrid catalysts displaying enhanced stability during the direct DME synthesis from syngas is presented. The adopted preparation strategy was based on the effective confinement of the copper catalyst within the pores of an SBA-15 silica carrier (dpore=7.0nm) prior to mixing with the acid zeolite. In order to maximize the Cu–ZnO interface area (where active Cu0 sites are likely located) the walls of the SBA-15 silica were coated with a near-monolayer of ZnO (17wt% Zn) prior the incorporation of copper (in concentrations of 10, 15, and 20wt%) by the so-called ammonia-driving deposition–precipitation (ADP) method. Copper nanoparticles sizing 5–6nm after H2-reduction (HRTEM) were effectively confined inside the SBA-15 mesopores (as supported by HAADF-STEM) for Cu loadings of up to 15wt%. Higher Cu loadings (20wt%) lead to large, XRD-visible, CuO nanoparticles residing out of the SBA-15 pores. The confined catalyst loaded with 15wt% Cu (15Cu/Zn@S15) displayed the highest Cu0 surface area (determined by N2O-RFC) and methanol synthesis activity. Then, hybrid catalysts based on this methanol synthesis function (15Cu/Zn@S15+Z5) were prepared in a 15Cu/Zn@S15:Z5 mass ratio of 2:1 by two methods: (a) grinding the mixture of powders prior to pelletizing (method G), and (b) mixing the pre-pelletized components (method M). Equivalent hybrids comprising a conventional coprecipitated Cu–ZnO–Al2O3 (CZA) catalyst were also prepared for comparative purposes (CZA+Z5). The catalysts were evaluated for direct DME synthesis (533K, 4.0MPa) in runs lasting ca. 24h. It was found that the confined 15Cu/Zn@S15+Z5 hybrids deactivated at a much lower rate than those based on CZA regardless the method of preparation. In turn, while conventional CZA+Z5 catalysts prepared by grinding (G) experienced a higher deactivation than that obtained by mixing (M) due to the contribution of detrimental interactions between the copper and zeolite components in the former, no differences in the deactivation rate were observed for the 15Cu/Zn@S15+Z5 hybrids prepared by grinding and mixing. The improved stability of these hybrid catalysts is accounted for by the inhibition of both detrimental interactions (by avoiding the direct contact of copper active sites and the zeolite surface) and extensive metal sintering (by limiting the extent of Cu0 crystal growth) induced by the effective confinement of the Cu-based catalyst within the SBA-15 pores.

Simultaneous determination of carcinoembryonic antigen and α-fetoprotein using an ITO immunoelectrode modified with gold nanoparticles and mesoporous silica

We report on an electrochemical immunoassay for simultaneous detection of the tumor markers carcinoembryonic antigen (CEA) and α-fetoprotein (AFP). Gold nanoparticles (AuNPs) were synthesized inside the internal pore walls of mesoporous silica (MPS). Then, Methylene blue (MB) and 6-ferrocenylhexanethiol (FeC), which act as electrochemical substrates, were incorporated into the channels via the formation of Au-S bonds. Finally, monoclonal antibodies against CEA (anti-CEA) and AFP (anti-AFP) were immobilized in the channels of MB-AuNPs-MPS and FeC-AuNPs-MPS, respectively. Suspensions of anti-CEA/MB-AuNPs-MPS and of anti-AFP/FeC-AuNPs-MPS were deposited on two different sites of the ITO electrode. When incubated with samples containing the two analytes, the formation of electrically nonconductive immunoconjugates blocks electron transfer. Simultaneous detection of CEA and AFP was accomplished by monitoring the current change before and after an immunoreaction has occurred. The AuNPs confined inside the channels are promoting the electron transport and thus improve detection limits. The immunoelectrode responds to CEA in the 0.5–50 ng mL−1 concentration range, and to AFP in concentrations between 0.5 and 100 ng mL−1. The detection limits (at an S/N of 3) are 0.1 ng mL−1 in both cases.

On Tuning the Fluorescence Emission of Porphyrin Free Bases Bonded to the Pore Walls of Organo-Modified Silica

A sol-gel methodology has been duly developed in order to perform a controlled covalent coupling of tetrapyrrole macrocycles (e.g., porphyrins, phthalocyanines, naphthalocyanines, chlorophyll, etc.) to the pores of metal oxide networks. The resulting absorption and emission spectra intensities in the UV-VIS-NIR range have been found to depend on the polarity existing inside the pores of the network; in turn, this polarization can be tuned through the attachment of organic substituents to the tetrapyrrrole macrocycles before bonding them to the pore network. The paper shows clear evidence of the real possibility of maximizing fluorescence emissions from metal-free bases of substituted tetraphenylporphyrins, especially when these molecules are bonded to the walls of functionalized silica surfaces via the attachment of alkyl or aryl groups arising from the addition of organo-modified alkoxides.

Iridium–Bismuth Cluster Complexes Yield Bimetallic Nano-Catalysts for the Direct Oxidation of 3-Picoline to Niacin

The reaction of Ir3(CO)9(μ3-Bi), 1, with BiPh3 has yielded a iridium–bismuth cluster complex Ir5(CO)10(μ3-Bi)2(μ4-Bi), 2. The first examples of bimetallic iridium–bismuth nanoparticles have been subsequently synthesized from 1 and 2, and these have been securely anchored onto the inner walls of mesoporous silica. These isolated, bimetallic iridium–bismuth nanoparticles display a superior catalytic performance, when compared to their analogous monometallic counterparts and equivalent physical mixtures, in the C–H activation of 3-picoline to yield niacin.

Sulfur- and Nitrogen-Doped, Ferrocene-Derived Mesoporous Carbons with Efficient Electrochemical Reduction of Oxygen

Development of inexpensive and sustainable cathode catalysts that can efficiently catalyze the oxygen reduction reaction (ORR) is of significance in practical application of fuel cells. Herein we report the synthesis of sulfur and nitrogen dual-doped, ordered mesoporous carbon (SN-OMCs), which shows outstanding ORR electrocatalytic properties. The material was synthesized from a surface-templating process of ferrocene within the channel walls of SBA-15 mesoporous silica by carbonization, followed by in situ heteroatomic doping with sulfur- and nitrogen-containing vapors. After etching away the metal and silica template, the resulting material features distinctive bimodal mesoporous carbon frameworks with high nitrogen Brunauer-Emmett-Teller specific surface area (of up to ∼1100 m(2)/g) and uniform distribution of sulfur and nitrogen dopants. When employed as a noble-metal-free electrocatalyst for the ORR, such SN-OMC shows a remarkable electrocatalytic activity; improved durability and better resistance toward methanol crossover in oxygen reduction can be observed. More importantly, it performs a low onset voltage and an efficient nearly complete four-electron ORR process very similar to the observations in commercial 20 wt % Pt/C catalyst. In addition, we also found that the textural mesostructure of the catalyst has superseded the chemically bonded dopants to be the key factor in controlling the ORR performance.

Preparation of titanium-grafted magnetic mesoporous silica for the enrichment of endogenous serum phosphopeptides

As one of the most important post-translational modifications, reversible phosphorylation of protein plays crucial roles in a large number of biological processes. Moreover, endogenous phosphopeptides are also associated with certain human diseases. An efficient enrichment and separation method is the premise for successful identification and quantification of phosphopeptides. In this work, titanium grafted magnetic mesoporous silica (Fe3O4@Ti-mSiO2) was developed and applied for the enrichment of endogenous phosphopeptides. Fe3O4@Ti-mSiO2 particles were prepared by grafting titanocene dichloride on the inner walls of magnetic mesoporous silica and then being calcined to remove cyclopentadienyl ligand. The physicochemical properties of the prepared materials were characterized by energy dispersive X-ray spectroscopy (EDX), nitrogen adsorption–desorption analysis, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). For selective enrichment of phosphopeptides, the prepared Fe3O4@Ti-mSiO2 particles were applied for tryptic digests of β-casein, mixtures of β-casein and bovine serum albumin (BSA), and low-fat milk. Finally, Fe3O4@Ti-mSiO2 was successfully applied for the enrichment of endogenous phosphopeptides from human serum.