Immunosensors for quantifying cyclooxygenase 2 pain biomarkers

• Published in: Clinica chimica acta 2011-07, Vol.412 (15-16), p.1391-1398
• Main Authors: Noah, Naumih M., Mwilu, Samuel K., Sadik, Omowunmi A., Fatah, Alim A., Arcilesi, Richard D.
• Format: Article
• Language: English
• Subjects: Affinity; Antibodies - analysis; Antibodies - immunology; Antigen-Antibody Reactions; Biomarkers - analysis; Biosensing Techniques - methods; COX-2; Cyclooxygenase 2 - analysis; Cyclooxygenase 2 - immunology; Humans; Pain biomarkers; Recombinant Proteins - analysis; Recombinant Proteins - immunology; Sensors; Serum Albumin, Bovine - analysis; Surface Plasmon Resonance
• ISSN: 0009-8981; 1873-3492
• DOI: 10.1016/j.cca.2011.04.017

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. 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. UPAC fluorescence signals were directly proportional to COX-2 at a linear range of 7.46×10−4–7.46×101ng/ml with detection limit of 1.02×10−4ng/ml. With SPR a linear range was 3.64×10−4–3.64×102ng/ml was recorded and a detection limit of 1.35×10−4ng/ml. Validation was achieved in simulated blood samples with percent recoveries of 81.39% and 87.23% for SPR and UPAC respectively. The developed sensors have the potential to provide objective characterization of pain biomarkers for clinical diagnoses.