title: Development of immunosensors for direct detection of three wound infection biomarkers at point of care using electrochemical impedance spectroscopy.
abstract: 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.
authors.affiliation: School of Chemistry & EaStCHEM, The University of Edinburgh, Joseph Black Building, King's Buildings, West Mains Road, Edinburgh EH9 3JJ, UK.
authors.forename: Ilenia
authors.initials: I
authors.lastname: Ciani
authors.forename: Holger
authors.initials: H
authors.lastname: Schulze
authors.forename: Damion K
authors.initials: DK
authors.lastname: Corrigan
authors.forename: Grace
authors.initials: G
authors.lastname: Henihan
authors.forename: Gerard
authors.initials: G
authors.lastname: Giraud
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Terry
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Walton
authors.forename: Ronald
authors.initials: R
authors.lastname: Pethig
authors.forename: Peter
authors.initials: P
authors.lastname: Ghazal
authors.forename: Jason
authors.initials: J
authors.lastname: Crain
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Campbell
authors.forename: Till T
authors.initials: TT
authors.lastname: Bachmann
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Mount
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D016207:Cytokines / Q000032:analysis* / Q000276:immunology; D058266:Dielectric Spectroscopy / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D019095:Point-of-Care Systems; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014946:Wound Infection / Q000175:diagnosis / Q000276:immunology*
chemical_list: D015415:Biomarkers; D016207:Cytokines