title: Immunosensors for quantifying cyclooxygenase 2 pain biomarkers.
abstract: BACKGROUND
  Cyclooxygenase 2 (COX-2) is a key enzyme in pain biomarkers, inflammation and cancer cell proliferation. Thus biosensors that can quantify pain mediators based on biochemical mechanism are imperative.
  
  
  METHODS
  Biomolecular recognition and affinity of antigenic COX-2 with the antibody were investigated using surface plasmon resonance (SPR) and ultra-sensitive portable capillary (UPAC) fluorescence sensors. Polyclonal goat anti-COX-2 (human) antibodies were covalently immobilized on gold SPR surface and direct recognition for the COX-2 antigen assessed. The UPAC sensor utilized an indirect sandwich design involving covalently attached goat anti-COX-2 as the capture antibody and rabbit anti-COX-2 (human) antibody as the secondary antibody.
  
  
  RESULTS
  UPAC fluorescence signals were directly proportional to COX-2 at a linear range of 7.46×10⁻⁴-7.46×10¹ ng/ml with detection limit of 1.02×10⁻⁴ ng/ml. With SPR a linear range was 3.64×10⁻⁴-3.64×10² ng/ml was recorded and a detection limit of 1.35×10⁻⁴ ng/ml. Validation was achieved in simulated blood samples with percent recoveries of 81.39% and 87.23% for SPR and UPAC respectively.
  
  
  CONCLUSIONS
  The developed sensors have the potential to provide objective characterization of pain biomarkers for clinical diagnoses.
authors.affiliation: Center for Advanced Sensors & Environmental Systems (CASE), Department of Chemistry, State University of New York at Binghamton, P. O. Box 6000, Binghamton, NY 13902, USA.
authors.forename: Naumih M
authors.initials: NM
authors.lastname: Noah
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Mwilu
authors.forename: Omowunmi A
authors.initials: OA
authors.lastname: Sadik
authors.forename: Alim A
authors.initials: AA
authors.lastname: Fatah
authors.forename: Richard D
authors.initials: RD
authors.lastname: Arcilesi
mesh_terms: D000906:Antibodies / Q000032:analysis / Q000276:immunology; D000937:Antigen-Antibody Reactions; D015415:Biomarkers / Q000032:analysis*; D015374:Biosensing Techniques / Q000379:methods*; D051546:Cyclooxygenase 2 / Q000032:analysis* / Q000276:immunology; D006801:Humans; D011994:Recombinant Proteins / Q000032:analysis / Q000276:immunology; D012710:Serum Albumin, Bovine / Q000032:analysis; D020349:Surface Plasmon Resonance
chemical_list: D000906:Antibodies; D015415:Biomarkers; D011994:Recombinant Proteins; D012710:Serum Albumin, Bovine; D051546:Cyclooxygenase 2