title: A fluorescent imaging assay of cast in renal disease based on graphene quantum dots and Fe3O4 nanoparticles.
abstract: BACKGROUND
  Renal disease has become a global public health problem. Cast is a useful disease marker of kidney injury and renal failure. Hence, a cast-targeted fluorescent imaging assay is developed for the laboratory diagnosis of renal disease.
  
  
  METHODS
  Firstly, graphene quantum dots (GQDs) were stripped from graphene oxide sheets and amine-modified. Then, anti-human IgG antibody was conjugated with Fe3O4 nanoparticles to identify the cast in urine. Furthermore, the modified GQDs were linked onto the surface of Fe3O4/anti-IgG nanocomposites. Lastly, this Fe3O4/GQD fluorescent probe was added into the sample to detect the cast through fluorescent imaging.
  
  
  RESULTS
  Preliminary application of this probe in clinical detection showed that the common types of casts in urine (including RBC, WBC, fatty and granular casts) could be detected by this fluorescent imaging assay. The method has the advantages of fast speed, high sensitivity (lowest detection limit to 2 casts/ml), good selectivity, and wide linear range (2-2000 casts/ml). Regression analysis also showed that there was a good linear relationship (y=0.9495×+10.974, R(2)=0.9879) between the fluorescent counts and the casts in urine.
  
  
  CONCLUSIONS
  This cast-targeted fluorescent imaging assay may be a potential method for the laboratory diagnosis of renal disease.
authors.affiliation: Department of Clinical Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Dongneng
authors.initials: D
authors.lastname: Jiang
authors.affiliation: Department of Clinical Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Danni
authors.initials: D
authors.lastname: Ni
authors.affiliation: Department of Clinical Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Clinical Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Liqun
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Clinical Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Clinical Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China. Electronic address: xqyyjyk@foxmail.com.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Pu
mesh_terms: D003952:Diagnostic Imaging; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis* / Q000652:urine*; D058185:Magnetite Nanoparticles / Q000737:chemistry; D010316:Particle Size; D045663:Quantum Dots; D012044:Regression Analysis; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties
chemical_list: D005456:Fluorescent Dyes; D058185:Magnetite Nanoparticles; D006108:Graphite
keywords: Cast; Fluorescent imaging; Graphene quantum dots; Laboratory diagnosis; Renal disease