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

• Published in: Biosensors & bioelectronics 2012-01, Vol.31 (1), p.413-418
• Main Authors: Ciani, Ilenia, Schulze, Holger, Corrigan, Damion K., Henihan, Grace, Giraud, Gerard, Terry, Jonathan G., Walton, Anthony J., Pethig, Ronald, Ghazal, Peter, Crain, Jason, Campbell, Colin J., Bachmann, Till T., Mount, Andrew R.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Biomarkers - analysis; Biosensing Techniques - instrumentation; Biosensors; Biotechnology; Chronic wound infection; Conductometry - instrumentation; Cytokines - analysis; Cytokines - immunology; Dielectric Spectroscopy - instrumentation; Equipment Design; Equipment Failure Analysis; Fundamental and applied biological sciences. Psychology; Humans; Immunoassay - instrumentation; Immunosensor; Impedimetric biosensor; Label free detection; Methods. Procedures. Technologies; Mock wound fluid; Multiparameter; Point-of-Care Systems; Reproducibility of Results; Sensitivity and Specificity; Various methods and equipments; Wound Infection - diagnosis; Wound Infection - immunology
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2011.11.004

► We develop a method for label-free electrochemical impedance immunosensing. ► We apply this method to the detection of three infection biomarkers. ► We show this can detect directly from biological matrices. ► We demonstrate the required sensitivity for rapid and clinically relevant wound infection detection. 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 3.3pM for TREM-1, 1.1nM for MMP-9 and 1.4nM 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.