title: Highly selective enrichment of phosphopeptides with high-index facets exposed octahedral tin dioxide nanoparticles for mass spectrometric analysis.
abstract: High-index facets exposed octahedral tin dioxide (SnO2) nanoparticles were successfully synthesized and applied to selectively enrich phosphopeptides for mass spectrometric analysis. The high selectivity and capacity of the octahedral SnO2 nanoparticles were demonstrated by effectively enriching phosphopeptides from digests of phosphoprotein (α- or β-casein), protein mixtures of β-casein and bovine serum albumin, milk, and human serum samples. The unique octahedral SnO2 with abundant unsaturated coordination Sn atoms exhibited enhanced affinity and selective coordination ability with phosphopeptides due to their high chemical activity. The strong affinity led to highly selective capture and enrichment of phosphopeptides for sensitive detection through the bidentate bonds formed between surface atoms and phosphate. The phosphopeptides could be detected in β-casein down to 4 × 10(-9)M or in the mixture of β-casein and BSA with a molar ratio of even 1:100. The performance in selective enrichment of phosphopeptides from drinking milk and human serum showed powerful evidence of high selectivity and efficiency in identifying the low-abundant phosphopeptides from complicated biological samples. This work provided a way to improve the physical and chemical properties of materials by tailoring their exposed facets for selective enrichment of phosphopeptides.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Rongna
authors.initials: R
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Hu
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong Kong, PR China.
authors.forename: Zongwei
authors.initials: Z
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China. Electronic address: hxju@nju.edu.cn.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
mesh_terms: D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D053768:Metal Nanoparticles; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010748:Phosphopeptides / Q000032:analysis*; D010766:Phosphorylation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D017971:Tin Compounds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D010748:Phosphopeptides; D017971:Tin Compounds; C045358:stannic oxide
keywords: Enrichment; Matrix-assisted laser desorption/ionization mass spectrometry; Phosphopeptide; Tin dioxide