Acid In Phosphate Buffer Solution Research Articles

PTA/CeO2@Pt-based electrochemical sensors to detect xanthine and uric acid, and evaluate fish freshness

In the present study, we constructed an electrochemical sensor using three materials, namely, cerium dioxide (CeO2) composite platinum (Pt) and polymer 3-amino-5-mercapto-1,2,4-triazole (PTA), prepared by hydrothermal method, to detect xanthines and uric acid. Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier infrared spectroscopy (FT-IR) were used to characterize the morphology, elemental composition, and structure of materials. The results demonstrated that the PTA/CeO2@Pt composites were prepared. The electrochemical behavior of xanthines and uric acid on PTA/CeO2@Pt composite electrodes was assessed by cyclic voltammetry (CV) and differential pulsed voltammetry (DPV). The results demonstrated that the dropping amount was 20 µL under a phosphoric acid buffer solution (pH 6). The peak current of xanthine (XA) demonstrated two good linear relationships with concentration, the linear regression equation was IXA = 0.3265CXA + 8.1967 R2 = 0.994 in the concentration range of 10–138 µmol/L, whereas it was IXA = 3.9884CXA + 51.661 R2 = 0.992 in the concentration range of 139–330 µmol/L. The detection limit was 10.36 × 10–7 M. The freshness of fish meat was evaluated, and the correlation analysis between evaluation results and results of xanthine detection in fish meat by PTA/CeO2@Pt electrochemical sensor demonstrated that r = 0.945 and P < 0.01 had a good correlation. The sensor could be used to determine the xanthine content in fish to reflect the freshness of fish, thus displaying good application prospects.

Protection of Si Nanowires against Aβ Toxicity by the Inhibition of Aβ Aggregation.

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by the accumulation of amyloid beta (Aβ) plaques in the brain. Aβ1-42 is the main component of Aβ plaque, which is toxic to neuronal cells. Si nanowires (Si NWs) have the advantages of small particle size, high specific surface area, and good biocompatibility, and have potential application prospects in suppressing Aβ aggregation. In this study, we employed the vapor-liquid-solid (VLS) growth mechanism to grow Si NWs using Au nanoparticles as catalysts in a plasma-enhanced chemical vapor deposition (PECVD) system. Subsequently, these Si NWs were transferred to a phosphoric acid buffer solution (PBS). We found that Si NWs significantly reduced cell death in PC12 cells (rat adrenal pheochromocytoma cells) induced by Aβ1-42 oligomers via double staining with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and fluorescein diacetate/propyl iodide (FDA/PI). Most importantly, pre-incubated Si NWs largely prevented Aβ1-42 oligomer-induced PC12 cell death, suggesting that Si NWs exerts an anti-Aβ neuroprotective effect by inhibiting Aβ aggregation. The analysis of Fourier Transform Infrared (FTIR) results demonstrates that Si NWs reduce the toxicity of fibrils and oligomers by intervening in the formation of β-sheet structures, thereby protecting the viability of nerve cells. Our findings suggest that Si NWs may be a potential therapeutic agent for AD by protecting neuronal cells from the toxicity of Aβ1-42.

Analysis of Electrochemically Active Substances in Malvaceae Leaves via Electroanalytical Sensing Technology for Species Identification

Electrochemical analysis has become a new method for plant analysis in recent years. It can not only collect signals of electrochemically active substances in plant tissues, but can also be used to identify plant species. At the same time, the signals of electrochemically active substances in plant tissues can also be used to investigate plant phylogeny. In this work, we collected electrochemical finger patterns in Malvaceae leaves based on the established methodological strategy. After the second derivative treatment, the collected electrochemical fingerprints can show more obvious differences. Three different recognition models were used to attempt electrochemical fingerprinting. The results show that linear support vector classification can be used to identify species with high accuracy by combining the electrochemical fingerprint signals collected in the phosphoric acid buffer solution and acetic acid buffer solution. In addition, the fingerprint information collected by the electrochemical sensor is further used for phylogenetic investigation. The 18 species were divided into three clusters. Species of the same genus have been clustered together. Dendrogram obtained by electrochemical fingerprinting was used to compare previously reported results deduced from morphological and complete chloroplast genomes.

Composite Aerogel Comprised of Sodium Alginate and Bentonite via Supercritical CO2 Drying: An Efficient Adsorbent for Lysozyme.

To meet the demand for the separation of specific substances, the construction of porous composite aerogels with a high specific surface area and a strong adsorption capacity is still a challenge. Herein, a sodium alginate/bentonite composite aerogel was efficiently prepared through supercritical fluid drying. The aerogel’s volume shrank less during supercritical drying, maintaining its original three-dimensional mesh structure. The resulting aerogel had a large specific surface area (445 m2/g), a low density (0.059 g/cm3), and a large pore volume (3.617 cm3/g). Due to the fixation and intercalation effects, bentonite was uniformly dispersed in the sodium alginate matrixes. The adsorption of lysozyme by the composite aerogel was evaluated, and the results showed that the optimal adsorption pH was 8 when the pH of the phosphoric acid buffer solution was between pH = 5 and 8.5. The time for adsorption to reach equilibrium was 8 h. The adsorption capacity increased with the increase in bentonite content, and when the initial concentration of lysozyme was from 0.2 to 1.2 g/L, the adsorption capacity first increased and then stabilized, and the maximum adsorption amount was 697 mg/g. The adsorption behavior was simulated in the isothermal region, and the linear correlation coefficient of Langmuir isothermal adsorption fitting was found to be 0.997. Thus, this composite aerogel with strong adsorption capacity can be used as a good alternative to enzymatic adsorbents or immobilized materials.

The electrochemical sensor based on Cu/Co binuclear MOFs and PVP cross-linked derivative materials for the sensitive detection of luteolin and rutin

The precursor Cu@Co binuclear MOFs were synthesized by hydrothermal method and pyrolyzed to obtain a class of carbon materials (Cu@C@CoO). The obtained Cu@C@CoO were characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectra (Raman), then the electrochemical sensors for detecting luteolin and rutin were constructed by using the Cu@C@CoO as electrode modification material. The electrochemical performance of these sensors was investigated by electrochemical alternating impedance technique (EIS) and cyclic voltammetry (CV), and the electrochemical behavior of luteolin and rutin on different electrodes were examined by differential pulse voltammetry (DPV) in phosphoric acid buffer solution (PBS). The results showed that the electrode modified with the Cu@C@CoO which was pyrolyzed at 600 °C showed the best detection effect for luteolin and rutin. Under the first-rank experimental conditions, the linear range of response current with the concentration of luteolin and rutin was 0.005–10.0 μmol/L and 0.01–10.0 μmol/L, and the minimum detectability was calculated to be 0.113 ± 0.001 nmol/L and 0.418 ± 0.016 nmol/L (S/N = 3), respectively. In addition, the sensor performed well in actual samples detection.

Factors influencing the removal of patulin by cysteine

The removal of patulin in phosphoric acid buffer solution by cysteine was investigated. Cysteine could effectively decrease the patulin concentration at high acidic condition (pH 3.0–5.0) with the help of high temperature greater than 90 °C. Three removal mechanisms of patulin by cysteine under high acidic and high temperature conditions were deduced. Reaction temperature, pH of reactive media, molar ratio between cysteine and patulin, and reaction time were all the obvious factors influencing the removal efficiency of patulin, and the increase of any one factor could significantly improve the removal efficiency of patulin. The removal process of patulin could be simulated by the zero-order kinetic model, logarithmic model, and pseudo-first-order kinetic model, respectively, and the corresponding correlation coefficients (R2) were all greater than 0.90. Presently, this method can only be applied for the removal of patulin in contaminated water from washing fruits in juice processing industry due to the high treatment temperature more than 120 °C and the long detoxification time greater than 1 h.

Si-doped graphene nanosheets as a metal-free catalyst for electrochemical detection of nitroaromatic explosives

Si-doped graphene nanosheets (SiGNS) have been successfully constructed via high temperature annealing of graphene oxide and tetraethoxysilane mixture in a sealed glass ampoule. The Si atoms doped into graphene’s carbon network mainly existed as C3-Si-O and C2-Si-O2 configurations. The as-prepared SiGNS exhibited excellent electrochemical detection ability to nitroaromatic compounds in 0.1 M phosphoric acid buffer solution (PBS, pH = 8.0) via an electrochemical catalytic process. Five nitroaromatic compounds, including nitrobenzene, 2-nitrotoluene, 4-nitrotoluene, 2, 4-dinitrotoluene and 2, 4, 6-trinitrotoluene, were taken as the analyte to demonstrate the electrochemical catalytic ability of SiGNS. Density functional theory (DFT) calculation was carried out to explore the electrochemical catalytic mechanism of SiGNS. A hydrogen bond mediated electrochemical catalytic mechanism was proposed. Both the excellent electrical conductivity and the rich surface hydroxyl groups enhanced the electrochemical detection ability of SiGNS to nitroaromatic compounds. Si atoms in SiGNS played a key role for the excellent electrochemical detection ability of SiGNS due to most of the surface hydroxyl groups anchored on the Si atoms.

Characterization of Surface Interaction between Chitosan-modified Liposomes and Mucin Layer by Using CNT Probe AFM Method

In order to characterize the adhesion and deformation behavior between chitosan-modified liposomes and the mucin layer of the small intestine, mucin was coated on hydrophobic surface-modified carbon nanotube (CNT) probe of an atomic force microscope. The interaction between this mucin layer and the liposomes with or without chitosan modification in phosphoric acid buffer solution was determined by atomic force microscopy. The pH of the buffer solution was controlled at 2.8 and 7.0. The chitosan modification increased the attractive force between the liposomes and mucin layer during the separation process under both pH conditions. This result corresponded with that from a previous study about the liposome adhesion behavior on the surface of the small intestine of rats. By using the mucin-coated CNT probe, the long range and different types of attractive forces between the chitosan-modified liposomes and mucin layer was observed. Furthermore, the small-scaled deformation behavior change on the liposomal surfaces due to chitosan modification was also observed by the CNT probe. The detail deformation and adhesion behavior of the liposomes with or without chitosan modification was detected.

Dependence of mechanism to thermodynamics in electrochemical oxidation of acetaminophen in the presence of different nucleophiles

In this work, electrochemical oxidations of three aminophenol species (4-aminophenol, N-methyl 4-aminophenol and acetaminophen) have been investigated both computationally and experimentally. The computational data were obtained using DFT (B3LYP) level of theory and 6-311G(d,p) basis set. Also, cyclic voltammetry and controlled potential coulometry were used to obtain the experimental results. The results indicate that the electrochemical oxidation potential of studied species (EpA) is dependence on ∆Gtot, and it increases upon increasing ∆Gtot. The ∆Gtot of studied species, calculated by the use of a general thermodynamic cycle, were used to mechanistic study of the electrochemical oxidation of acetaminophen in the presence of various nucleophiles. The results show that mechanisms of the electrochemical oxidation of acetaminophen in the presence of different nucleophiles are not the same, and the mechanisms are dependent on the ∆Gtot species which are produced during electrolysis. It was found that the mechanism of the electrochemical oxidation of acetaminophen in the presence of 2-thiobarbituric acid in phosphate buffer solution is ECEC and in a buffer solution/acetonitrile mixture is ECECE. Finally, the calculated results were used to predict the electrochemical oxidation mechanisms of acetaminophen in the presence of 4-mercaptocoumarin, pyridine and cyanide ion as nucleophiles.

Near-infrared BODIPY-paclitaxel conjugates assembling organic nanoparticles for chemotherapy and bioimaging

Self-assembly of organic molecules has attracted more and more attention because of precise molecular structure and multifarious synthesis chemistry. Herein, near-infrared brominated boron-dipyrromethenes (BODIPY) paclitaxel conjugate (BrBDP-2PTX) was synthesized. BrBDP-2PTX could self-assemble into uniform spherical nanoparticles (BrBDP-2PTX NPs) via nanoprecipition method. The obtained nanoparticles showed satisfying stability in aqueous solution and 10% fetal bovine serum (FBS) containing phosphoric acid buffer solution (PBS). Moreover, BrBDP-2PTX NPs could make rapid enzyme response to Proteinase K as evidenced by the obvious changes in size and size distribution. BrBDP-2PTX NPs could be internalized by the HeLa cells and exhibited potent cytotoxicity toward tumor cells (human cervical carcinoma cells and liver hepatocellular carcinoma cells) as revealed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assays and live/dead staining. Furthermore, in vivo experiments indicated BrBDP-2PTX NPs could be used as efficient bioimaging agents without causing any systemic toxicity. This work highlights the potential of using self-assembly of small organic molecules to develop functional nanomaterials.

Sodium Dodecyl Sulphate/Poly(Brilliant Blue)/Multi Walled Carbon Nanotube Modified Carbon Paste Electrode for the Voltammetric Resolution of Dopamine in the Presence of Ascorbic Acid and Uric Acid

Sodium dodecyl sulphate/poly(brilliant blue)/multi walled carbon nanotube modified carbon paste electrode was fabricated for the electroanalysis of dopamine in the presence of ascorbic acid and uric acid in phosphate buffer solution of pH 7.4. The key parameters such as sensitivity, selectivity, antifouling property and stability were achievedby the modified electrode. The redox peaks obtained at modified electrode shows good electrocatalytic activity towards the oxidation of dopamine. From the effect of scan rateand concentration the electrode phenomenon was confirmed to be adsorption-controlled process. The lower limit of detection of dopamine was 2.69 × 10-7M, and the simultaneous analysis shows a good result with peak to peak separation between dopamine and other two analytes ascorbic acid and uric acid by both cyclic voltammetry and differential pulse voltammetric techniques.

Voltammetric Resolution of Dopamine in Presence of Ascorbic Acid and Uric Acid at Poly (Brilliant Blue) Modified Carbon Paste Electrode

Poly (brilliant blue) modified carbon paste electrode was fabricated for the detection of dopamine in the presence of large excess of ascorbic acid and uric acid in phosphate buffer solution of pH 7.4. The redox peaks obtained at poly (brilliant blue) modified carbon paste electrode shows good electrocatalytic activity towards the oxidation of dopamine. From the study of scan rate variation the electrode process was found to be adsorption controlled. The limit of detection of dopamine was found to be 6.7 × 10-7 M. and the simultaneous study shows the good result with peak to peak separation between dopamine and other two analytes ascorbic acid and uric acid by both cyclic voltammetry and differential pulse voltammetric techniques

Study of Pretreatment and Analysis Method in Detecting TN in Waste Water by HPLC

This paper presents a method combined of HPLC and DAD in detecting the total nitrogen index in urban waste water and studies the digestion condition of the sample pretreatment. The result shows that after pressurized digestion and adjusting pH to around 7.0 with phosphoric acid buffer solution, the sample can be applied chromatographic analysis. The chromatographic analysis is conducted with phosphoric acid buffer solution-acetonitrile as the mobile phase, flow velocity 0.8mL.min-1, column temperature 30 °C, intake-sample volume 10 μL,with ODS as the stationary phase, and the sample is detected with wavelength of 208nm. The linearly dependent coefficient of standard curve is 0.9971, the linearity range is 0.10-30.0mg·L-1, relative standard deviation (RSD) is less than 12%, the recycle rate is 107-159%,detection limit (S/N=2.4) reaches 0.05ng.

Functionalization of Magnetic Nanoparticles with Dendritic–Linear–Brush-Like Triblock Copolymers and Their Drug Release Properties

Novel water-soluble dendritic-linear-brush-like triblock copolymer polyamidoamine-b-poly(2-(dimethylamino)ethyl methacrylate)-b-poly(poly(ethylene glycol) methyl ether methacrylate) (PAMAM-b-PDMAEMA-b-PPEGMA)-grafted superparamagnetic iron oxide nanoparticles (SPIONs) were successfully prepared via a two-step copper-mediated atom transfer radical polymerization (ATRP) method. The macroinitiators were immobilized on the surface of Fe(3)O(4) nanoparticles via effective ligand exchange of oleic acid with the propargyl focal point PAMAM-typed dendron (generation 2.0, denoted as propargyl-D(2.0)) containing four carboxyl acid end groups, following a click reaction with 2'-azidoethyl-2-bromoisobutylate (AEBIB). PDMAEMA and PPEGMA were grown gradually from nanoparticle surfaces using the "grafting from" approach, which rendered the SPIONs soluble in water and reversed aggregation. To the best of our knowledge, this is the first report that describes the functionalization of magnetic nanoparticles with dendritic-linear-brush-like triblock copolymers. The modified nanoparticles were systematically studied via TEM, FT-IR, DLS, XRD, NMR, TGA, and magnetization measurements. DLS measurement confirmed that the obtained dendritic-linear-brush-like triblock copolymer-grafted SPIONs had a uniform hydrodynamic particle size of average diameter less than 30 nm. The dendritic-linear-brush-like triblock copolymer-grafted SPIONs possessed excellent biocompatibility by methyl tetrazolium (MTT) assays against NIH3T3 cells and hemolysis assays with rabbit erythrocytes. Furthermore, an anticancer drug, doxorubicin (Dox), was used as a model drug and loaded into the dendritic-linear-brush-like triblock copolymer-grafted SPIONs, and subsequently, the drug releases were performed in phosphoric acid buffer solution pH = 4.7, 7.4, or 11.0 at 37 °C. The results verify that the dendritic-linear-brush-like triblock copolymer-grafted SPIONs possess pH-responsive drug release behavior. The Dox dose of the loaded and free drug required for 50% cellular growth inhibition was 2.72 and 0.72 μm/mL, respectively, according to MTT assay against a Hella cell line in vitro. Therefore, on the basis of its biocompatibility and drug release effect, the modified SPION could provide a charming opportunity to design some excellent drug delivery systems for therapeutic applications.

Adsorption-induced polymerization of 3-methylthiophene at silver-coated glass surfaces and electroactive characteristics

The adsorption-induced polymerization of 3-methylthiophene (3MT) on silver vapor-deposited glass surfaces is investigated using micro Raman scattering and UV–Vis reflection spectroscopy. Both techniques provide the evidence of an adsorption-induced polymerization mechanism of these molecules, indicating that the orientation of 3MT molecules randomly distributes in the bulk poly(3-methylthiophene) film. The kinetics of 3MT adsorption-induced polymerization is also studied using Auger electron spectroscopy. The adsorption-induced polymerization process shows constant adsorption rate (0.15 nm min −1) within adsorption time of 1 h. Moreover, the electroactive characteristics of P3MT are employed to detect uric acid in phosphate buffer solution.

Voltammetric Detection of Dopamine in Presence of Ascorbic Acid and Uric Acid at Poly (Xylenol Orange) Film-Coated Graphite Pencil Electrode

Poly (xylenol orange) film-coated graphite pencil electrode was fabricated for the detection of dopamine in the presence of ascorbic acid and uric acid in phosphate buffer solution of pH 7. The redox peaks obtained at modified electrode shows a good enhancement. The scan rate effect was found to be a diffusion-controlled electrode process. The electrochemical oxidation of dopamine was depended on pH, and the limit of detection was found to be 9.1×10−8 M. The simultaneous study gave and excellent result with great potential difference between dopamine and other bioactive organic molecules by using both cyclic voltammetric and differential pulse voltammetric techniques. The present modified graphite electrode was applied to the detection of dopamine in the injection samples, and the recovery obtained was satisfactory.

Water-soluble dendritic-linear triblock copolymer-modified magnetic nanoparticles: preparation, characterization and drug release properties

One route has been employed to prepare dendritic-linear block copolymer modified superparamagnetic iron oxide nanoparticles (SPIONs), which consist of a Fe3O4 magnetic nanoparticle core and a dendritic-linear block copolymer, the focal point polyamidoamine-type dendron-b-poly(2-dimethylaminoethyl methacrylate)-b-poly(N-isopropylacrylamide) (PAMAM-b-PDMAEMA-b-PNIPAM) shell by two-step atom transfer radical polymerization (ATRP). Firstly, Fe3O4 nanoparticles were prepared by a high-temperature solution phase reaction in the presence of iron(III) acetylacetonate [Fe(acac)3], oleic acid and oleylamine. Then propargyl focal point PAMAM-type dendron (generation 2.0, denoted as propargyl-D2.0) with four carboxyl acid end groups as a cap displaced the oleic acid and oleylamine on the surfaces. Subsequently, an initiator for ATRP was introduced onto the propargyl-D2.0-modified Fe3O4 nanoparticle surfaces via click chemistry with 2′-azidoethyl-2-bromoisobutylate (AEBIB). PDMAEMA and PNIPAM were grown gradually from nanoparticle surfaces using two-step copper-mediated ATRP. Finally, a crosslinking reaction between PDMAEMA block with 1,2-bis(2-iodoethoxy)ethane (BIEE) was used to stabilize the nanoparticles and reverse aggregation. The modified nanoparticles were subjected to detailed characterization using FT-IR, DLS, XRD and TGA. Magnetization measurements confirmed the characteristic superparamagnetic behavior of all magnetic nanoparticles under room temperature. In addition, doxorubicin (DOX) as an anticancer drug model was loaded into the dendritic-linear block copolymer shell of the modified nanoparticles, and subsequently the drug release was performed in phosphoric acid buffer solution (pH 7.4) at 25 °C or 37 °C. The results verify that dendritic-linear block copolymer-modified nanoparticles as a drug carrier possess thermosensitive drug release behaviors. Furthermore, a methyl tetrazolium (MTT) assay of DOX-loaded dendritic-linear block copolymer-modified nanoparticles against Hela cells was evaluated. The results show that the modified nanoparticles can be used for drug delivery.

Bilirubin adsorption property of mesoporous silica and amine-grafted mesoporous silica

Nephritic, hepatic and immune failures would lead to the overload of endogenous toxic molecules (e.g. bilirubin, cholic acid, uric acid, creatinine etc.) in human bodies. It is fatal in most cases and extracorporeal blood purification (ECBP) is powerful first-aid therapy. Adsorbents are key parts of ECBP apparatus. Mesoporous silicas should be promising candidates for these medical adsorbents, but there is no report about this. Herein, pure and amine-grafted mesoporous silicas have been applied to adsorb bilirubin, cholic acid, uric acid, creatinine and phenobarbital for the first time. These mesoporous materials show high adsorption capacities for bilirubin and uric acid in phosphate buffer solution (PBS). Effects of pore sizes, amine-modification, temperature and ionic strength on their bilirubin adsorption capacities have been studied in detail.

Manganese oxide nanocomposites with improved surface area prepared by one-pot surfactant route for electro catalytic and biosensor applications

Braunite phase manganese oxide is naturally available in manganese–silicate rocks with minor amount of silicate content. New synthetic route is attempted to prepare the manganese oxide nanoparticle and silica incorporated manganese oxide nanocomposite in the present study. XRD patterns reveal the braunite phase formation for as synthesized manganese oxide nanocomposite and silica incorporated MnO2 nanocomposite materials. Improved BET surface area values are achieved by one step surfactant assisted method (i.e., 82 and 151 m2/g) compared to conventional route prepared manganese oxide nanomaterial. Flaky pastry type morphology was observed for as synthesized Si–MnO2 nanocomposites. Cyclic voltammetry studies predict the electrocatalytic activity of manganese oxide nanoparticle and Si–MnO2 nanocomposite in presence of electroactive redox couple. Si–MnO2 nanocomposite modified glassy carbon (GC) electrode shows the effective electroactive response in presence of Fe2+/Fe3+ redox couple at 0.69 V with current density of 0.343 × 10−5 A/cm2 compared to manganese oxide nanoparticle modified GC electrode. The biosensor responses for ascorbic acid have been tested in the present study and manganese oxide nanoparticle modified GC electrode shows effective response at low concentration of (1 × 10−5 M) ascorbic acid in phosphate buffer solution. Manganese oxide nanoparticle modified electrode shows the better response with current density value of 0.115 × 10−5 A/cm2 compared to Si–MnO2 nanocomposite.

Bilirubin adsorption property of mesoporous silica and amine-grafted mesoporous silica

Abstract Nephritic, hepatic and immune failures would lead to the overload of endogenous toxic molecules (e.g. bilirubin, cholic acid, uric acid, creatinine etc.) in human bodies. It is fatal in most cases and extracorporeal blood purification (ECBP) is powerful first-aid therapy. Adsorbents are key parts of ECBP apparatus. Mesoporous silicas should be promising candidates for these medical adsorbents, but there is no report about this. Herein, pure and amine-grafted mesoporous silicas have been applied to adsorb bilirubin, cholic acid, uric acid, creatinine and phenobarbital for the first time. These mesoporous materials show high adsorption capacities for bilirubin and uric acid in phosphate buffer solution (PBS). Effects of pore sizes, amine-modification, temperature and ionic strength on their bilirubin adsorption capacities have been studied in detail.