Aptamer-based biosensing probes for chemical imaging of multiple analytes at single cells - Project Summary/Abstract The Lazenby lab is an electroanalytical research group dedicated to introducing and developing new imaging modalities and sensing methodologies for the study of complex biological systems. Our research leverages the capabilities of electrochemical techniques to measure molecules in real time, with spatial resolution across various size scales. Electrochemical methods are suitable for examining redox-active analytes, but many biologically significant molecules don’t exhibit redox activity, meaning they can’t directly undergo electron transfer in a potential window that doesn’t oxidize or reduce the solvent (i.e. aqueous media). Also, selectivity and the number of analytes that can be detected is governed by the formal potential of the analytes of interest and other redox active species in solution. To broaden the scope of processes that can be monitored, our lab is building new methods to map and measure concentrations of various analytes to be applied to a range of cell lines. We are using aptamers as the biorecognition element in a variety of sensor platforms that take advantage of the ability to measure non-redox active analytes. These aptamer-based sensors have high specificity and sensitivity for a diverse range of analytes, including small molecules, drugs, metabolites, biomarkers and toxins. We are advancing the field by integrating these aptamer-based sensors into scanned probe microscopies, wherein the functionalized imaging probes will enable high spatial resolution mapping of both cellular and subcellular structures. Our lab is building a suite of imaging techniques, using different types of scanned probe that include aptamer-modified microelectrodes for mapping large areas, and aptamer-functionalized nanopipettes for probing subcellular features with high precision, and with the ability to measuring redox active analytes using traditional electrochemical methods. These capabilities are particularly well-suited for the study of complex biological processes that are challenging to observe using conventional methods. A key innovation in our lab’s approach is the multiplexing of these imaging probes, that enables the simultaneous real-time detection of multiple analytes. This will enable the concentrations of multiple analytes to be quantified, and even visualized, simultaneously by targeting where aptamers are immobilized on probes with multiple elements and exploiting the fact that a single potential waveform can be uniformly applied to any sensor of this type. Furthermore, we are coupling the sensors with ion conductance probes for topographic measurements of cells, and with electrodes for the detection of redox active species, and with potentiometric probes for local pH measurement. These integrated probes will greatly enhance our ability to study a broader range of biological systems than can currently be studied using existing imaging and multiplexing strategies. The outcomes of the proposed research have the potential to transform our understanding of complex biological processes, which paves the way for novel diagnostic tools and therapeutic strategies.
