title: The Evaluation of Colorectal Cancer Risk in Serum by anti-DESMIN-conjugated CdTe/CdS Quantum Dots.
abstract: BACKGROUND
  DESMIN is a novel prognostic predictor and therapeutic target for colorectal cancer (CRC). Enzyme-linked immunosorbent assay (ELISA) and electrochemiluminescence (ELC) assays are large-scale and highcost projects; therefore, it is necessary to develop a new, fast, and simple yet highly sensitive and specific method to detect DESMIN in serum. Semiconducting quantum dots (QDs) possess high fluorescence quantum yield, stability against photobleaching, and size-controlled luminescence properties, thus being utilized in photoelectrochemical tumor marker detection, especially in ameliorating the diagnostic value in complex biological ambient ionization. However, CdTe/CdS quantum dots (QDs) have not been applied in detecting DESMIN in serum.
  
  
  METHODS
  DESMIN in serum has been established using anti-DESMIN-conjugated CdTe/CdS quantum dots (QDs) and measurements. The assay sensitivity was determined by measurement of quenched fluorescence intensity of DESMIN at 0.1, 0.5, 1.0, 2.0, or 5.0 ng/mL in PBS or 0.25%, 0.5%, 1.0%, 2.0%, or 5% human serum diluted in PBS. The assay was optimized under different pH (7.00 - 7.40) for different reaction durations (10 - 60 minutes). The specificity of anti-DESMIN-QDs was determined by testing the interference of DESMIN activity with CEA, IgG, or AFP, each at 1 ng/mL.
  
  
  RESULTS
  Under the optimized incubation time (30 minutes) at room temperature and optimal pH 7.1 - 7.2, a correlation between the decreased fluorescence intensity of anti-DESMIN-conjugated CdTe/CdS QDs and the concentration of DESMIN in the range from 0.05 to 100 ng/mL, was established. The sensitivity for the detection of DESMIN in the range from 0.05 to 100 ng/mL, with a detection limit of 0.02 ng/mL. The assay presented a high specificity because the anti-DESMIN-conjugated CdTe/CdS QDs only reacted with ABR1B10 in the sera in the presence of CEA, IgG or AFP.
  
  
  CONCLUSIONS
  The immunofluorescence assay to detect DESMIN in serum using anti-DEMSIN-conjugated CdTe/ CdS QDs was fast and simple yet presented high sensitivity and specificity. Our method provides a promising tool for early prediction of CRC risk.
authors.forename: Yao
authors.initials: Y
authors.lastname: Wang
authors.forename: Yuanting
authors.initials: Y
authors.lastname: Li
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Chen
authors.forename: Tianhao
authors.initials: T
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Gu
authors.forename: Xianhua
authors.initials: X
authors.lastname: Wu
authors.forename: Yi
authors.initials: Y
authors.lastname: Yin
authors.forename: Maosheng
authors.initials: M
authors.lastname: Wang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Pan
mesh_terms: D019187:Cadmium Compounds; D015179:Colorectal Neoplasms; D003893:Desmin; D006801:Humans; D045663:Quantum Dots; D013691:Tellurium
chemical_list: D019187:Cadmium Compounds; D003893:Desmin; D013691:Tellurium