Design of a piezoelectric immunosensor for tuberculosis biomarker detection

Monoclonal antibodies have been applied in biomedical research for diagnosis of various diseases and for the treatment of increasing prevalence diseases such as tuberculosis. There is a need to develop systems capable of detecting tuberculosis-related biomarkers that can provide a quick diagnosis to begin treatment immediately. Thanks to the advances in research for detection, biosensors technologies are emerging as a good alternative for clinical applications. The aim of this work was to develop a piezoelectric immunosensor for rapid and efficient tuberculosis detection. To this purpose, 12 hybridomas and their secreted monoclonal antibodies specific for a biomarker of Mycobacterium tuberculosis were obtained as potential bio-receptors. The monoclonal antibody affinity to the antigenic protein of interest was tested by ELISA. Surface functionalization of the gold electrode - the transducer - of a Quartz Crystal Microbalance (QCM) was simulated by the formation of Self-Assembled Monolayers (SAM) of BSA as a model protein. The functionalized surface was image-characterized by Atomic Force Microscopy (AFM). The appropriate electronic instrumentation system for QCM characterization, with temperature control, was also developed. The obtained immunoreagents will be used as specific recognition bioactive molecules, in combination with functionalized quartz crystals, to build a piezoelectric immunosensor for the detection of Mycobacterium tuberculosis biomarkers, which can be related to the disease.