Abstract
Acoustic wave biosensors are a real-time, label-free biosensor technology, which have been exploited for the detection of proteins and cells. One of the conventional biosensor approaches involves the immobilization of a monolayer of antibodies onto the surface of the acoustic wave device for the detection of a specific analyte. The method described within includes at least two immobilizations of two different antibodies onto the surfaces of two separate acoustic wave devices for the detection of several analogous analytes. The chemical specificity of the molecular recognition event is achieved by virtue of the extremely high (nM to pM) binding affinity between the antibody and its antigen. In a standard ELISA (Enzyme-Linked ImmunoSorbent Assay) test, there are multiple steps and the end result is a measure of what is bound so tightly that it does not wash away easily. The fact that this "gold standard" is very much not real time, masks the dance that is the molecular recognition event. X-Ray Crystallographer, Ian Wilson, demonstrated more than a decade ago that antibodies undergo conformational change during a binding event[1, 2]. Further, it is known in the arena of immunochemistry that some antibodies exhibit significant cross-reactivity and this is widely termed antibody promiscuity. A third piece of the puzzle that we will exploit in our system of acoustic wave biosensors is the notion of chemical orthogonality. These three biochemical constructs, the dance, antibody promiscuity and chemical orthogonality will be combined in this paper with the notions of in-phase (I) and quadrature (Q) signals from digital radio to manifest an approach to molecular recognition that allows a level of discrimination and analysis unobtainable without the aggregate. As an example we present experimental data on the detection of TNT, RDX, C4, ammonium nitrate and musk oil from a system of antibody-coated acoustic wave sensors.
Highlights
Molecular recognition is at the core of it all
The results suggest that chemical orthogonal methods may be used as an analytical tool for the detection and differentiation among analogous molecules based on quadrature detection techniques for digital radio systems
In this paper three biochemical constructs, The Dance(i.e. conformational change and molecular recognition), antibody promiscuity and chemical orthogonality were combined with the concepts of inphase (I) and quadrature (Q) signals from digital radio to manifest an analytical biochemistry approach that allows us to convert a molecular recognition event into an electrical signal
Summary
Molecular recognition is at the core of it all. DNA is methylated when it serves the cell to cease transcription of a particular gene. The histone cores, around which the DNA is wound, are at times methylated so as to shut off transcription. Such a small molecular moiety, CH3, that if we were to attempt to glean its presence on DNA using standard analytical chemistry techniques in the presence of complex media we would be hard pressed to find success. In the molecular world of the cell this small modification changes everything. All this thanks to the mysteries of molecular recognition
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
