title: Highly selective manganese-doped zinc sulfide quantum dots based label free phosphorescent sensor for phosphopeptides in presence of zirconium (IV).
abstract: We report a room-temperature phosphorescence (RTP) sensor for phosphopeptides based on zirconium (IV)-modulated mercaptopropionic acid (MPA)-capped Mn-doped ZnS quantum dots (QDs). This sensor incorporates the advantages of the well-known Zr(4+)-phosphopeptide affinity pair and the RTP properties of doped QDs. The RTP of Mn-doped ZnS QDs capped with MPA can be effectively quenched by Zr(4+). The high affinity of phosphopeptides to Zr(4+) enables the dissociation of the ion from the surface of MPA-capped ZnS QDs, thereby forming a stable complex with phosphopeptides in the solution, and recovering the RTP of the QDs. The Zr(4+)-induced RTP quenching and subsequent phosphopeptide-induced RTP recovery for MPA-capped ZnS QDs provide a solid basis for the present RTP sensor based on QDs for the detection of phosphopeptides. The detection limit for phosphopeptides is 0.9ngmL(-1), the relative standard deviations is 2.5%, and the recovery of urine and serum samples with phosphopeptides addition rangs from 96% to 105% at optimal conditions. The proposed method was successfully applied to biological fluids and obtained satisfactory results.
authors.affiliation: Department of Chemistry, Shanxi Normal University, Linfen 041004, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Gong
authors.affiliation: Department of Chemistry, Shanxi Normal University, Linfen 041004, PR China. Electronic address: crush_bc@163.com.
authors.forename: Zhefeng
authors.initials: Z
authors.lastname: Fan
mesh_terms: D015097:3-Mercaptopropionic Acid; D015374:Biosensing Techniques / Q000379:methods*; D006801:Humans; D008163:Luminescent Measurements; D008345:Manganese; D010748:Phosphopeptides / Q000032:analysis* / Q000097:blood / Q000652:urine; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D013440:Sulfides; D017967:Zinc Compounds; D015040:Zirconium
chemical_list: D010748:Phosphopeptides; D013440:Sulfides; D017967:Zinc Compounds; D008345:Manganese; D015097:3-Mercaptopropionic Acid; D015040:Zirconium; C031238:zinc sulfide
keywords: MPA-capped Mn-doped quantum dots; Phosphopeptides; Room-temperature phosphorescence sensor; Zirconium (IV)