Development of immunosensors for direct detection of three wound infection biomarkers at point of care using electrochemical impedance spectroscopy

• DOI: 10.1016/j.bios.2011.11.004
• Publication Date: 2011-11-17T12:45:45Z
• Authors: Ilenia Ciani; Holger Schulze; Damion K. Corrigan; Grace Henihan; Gerard Giraud; Jonathan G. Terry; Anthony J. Walton; Ronald Pethig; Peter Ghazal; Jason Crain; Colin J. Campbell; Till T. Bachmann; Andrew R. Mount
• Keywords: Matrix (chemical analysis)

A method for label-free, electrochemical impedance immunosensing for the detection and quantification of three infection biomarkers in both buffer and directly in the defined model matrix of mock wound fluid is demonstrated. Triggering Receptor-1 Expressed on Myeloid cells (TREM-1) and Matrix MetalloPeptidase 9 (MMP-9) are detected via direct assay and N-3-oxo-dodecanoyl-l-HomoSerineLactone (HSL), relevant in bacterial quorum sensing, is detected using a competition assay. Detection is performed with gold screen-printed electrodes modified with a specific thiolated antibody. Detection is achieved in less than 1h straight from mock wound fluid without any extensive sample preparation steps. The limits of detection of 3.3 pM for TREM-1, 1.1 nM for MMP-9 and 1.4 nM for HSL are either near or below the threshold required to indicate infection. A relatively large dynamic range for sensor response is also found, consistent with interaction between neighbouring antibody-antigen complexes in the close-packed surface layer. Together, these three novel electrochemical immunosensors demonstrate viable multi-parameter sensing with the required sensitivity for rapid wound infection detection directly from a clinically relevant specimen.