title: Preparation of Keggin-type phosphomolybdate by a one-step solid-state reaction at room temperature and its application in protein adsorption.
abstract: Keggin-type phosphomolybdate ((C19H42N)3PMo12O40) is prepared by a one-step solid-state reaction at room temperature and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and elemental analysis. The as-prepared phosphomolybdate is demonstrated to be an efficient adsorbent for proteins. In this particular case, the selective adsorption of neutral protein hemoglobin is achieved. While under the same conditions virtually no adsorption of acidic and basic proteins, represented by bovine serum albumin and cytochrome c, are observed. A solid-phase extraction procedure is developed for the selective isolation of hemoglobin. At pH 6, a sorption efficiency of 91.4% is achieved for 100 μg/mL hemoglobin in 1.0 mL solution by using 5.0 mg of the phosphomolybdate. The adsorption behavior of hemoglobin fits well with a Langmuir adsorption model, corresponding to a theoretical adsorption capacity of 55.86 mg/g. The retained hemoglobin could be readily recovered by using a 60 mmol/L imidazole solution at pH 7, giving rise to a recovery of 64.7%. The practical application of phosphomolybdate for protein adsorption is demonstrated by the selective isolation of hemoglobin from human whole blood followed by a sodium dodecyl sulfate polyacrylamide gel electrophoresis assay.
authors.affiliation: Research Center for Analytical Sciences, College of Sciences, Northeastern University, Shenyang, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Chen
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Shen
authors.forename: Jie
authors.initials: J
authors.lastname: Xia
authors.forename: Xu-Wei
authors.initials: XW
authors.lastname: Chen
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D000818:Animals; D002417:Cattle; D045304:Cytochromes c / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D006454:Hemoglobins / Q000737:chemistry* / Q000302:isolation & purification; D006801:Humans; D008982:Molybdenum / Q000737:chemistry*; D010756:Phosphoric Acids / Q000138:chemical synthesis / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D052616:Solid Phase Extraction; D013499:Surface Properties; D013696:Temperature
chemical_list: D006454:Hemoglobins; D010756:Phosphoric Acids; D012710:Serum Albumin, Bovine; D008982:Molybdenum; D045304:Cytochromes c; C003125:phosphomolybdic acid
keywords: Hemoglobin; Isolation; Phosphomolybdate; Solid-phase extraction; Solid-state reaction