title: Ultrasensitive nanostructured immunosensor for stem and carcinoma cell pluripotency gatekeeper protein NANOG.
abstract: OBJECTIVE
  To develop an immunosensor for ultrasensitive detection of the NANOG protein. NANOG regulates pluripotency in stem cells and some cancer cells. This article reports the first electrochemical immunosensor for ultrasensitive detection and absolute quantification of the NANOG protein. The sensor features dense capture antibody-coated gold nanoparticle layers on a pyrolytic graphite underlayer.
  
  
  METHODS
  Two separate multilabel detection strategies were used to achieve moderate and ultra-high sensitivity.
  
  
  RESULTS
  Good sensitivity was achieved for NANOG over the concentration range 0.1-160 pg/ml. The moderate-sensitivity approach gave a detection limit of 25 pg/ml, while the ultrasensitive method achieved a 250-fold lower detection limit of 0.1 pg/ml. Amounts of NANOG detected in human embryonic stem cell lysates correlated well with qualitative western blots and mRNA expression.
  
  
  CONCLUSIONS
  The electrochemical gold nanoparticle immunosensor is suitable for measuring NANOG protein expression in stem and carcinoma cell tissue lysates at very low levels.
authors.affiliation: Department of Chemistry, University of Connecticut, CT 06269, USA.
authors.forename: Bhaskara V
authors.initials: BV
authors.lastname: Chikkaveeraiah
authors.forename: Alice
authors.initials: A
authors.lastname: Soldà
authors.forename: Dharamainder
authors.initials: D
authors.lastname: Choudhary
authors.forename: Flavio
authors.initials: F
authors.lastname: Maran
authors.forename: James F
authors.initials: JF
authors.lastname: Rusling
mesh_terms: D055910:Antibodies, Immobilized / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods*; D002460:Cell Line; D055664:Electrochemical Techniques / Q000379:methods; D053595:Embryonic Stem Cells / Q000378:metabolism*; D006046:Gold / Q000737:chemistry; D018398:Homeodomain Proteins / Q000032:analysis* / Q000276:immunology; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D000071317:Nanog Homeobox Protein
chemical_list: D055910:Antibodies, Immobilized; D018398:Homeodomain Proteins; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D006046:Gold