2 research outputs found
Local Delivery of Molecules from a Nanopipette for Quantitative Receptor Mapping on Live Cells
Using nanopipettes to locally deliver
molecules to the surface of living cells could potentially open up
studies of biological processes down to the level of single molecules.
However, in order to achieve precise and quantitative local delivery
it is essential to be able to determine the amount and distribution
of the molecules being delivered. In this work, we investigate how
the size of the nanopipette, the magnitude of the applied pressure
or voltage, which drives the delivery, and the distance to the underlying
surface influences the number and spatial distribution of the delivered
molecules. Analytical expressions describing the delivery are derived
and compared with the results from finite element simulations and
experiments on delivery from a 100 nm nanopipette in bulk solution
and to the surface of sensory neurons. We then developed a setup for
rapid and quantitative delivery to multiple subcellular areas, delivering
the molecule capsaicin to stimulate opening of Transient Receptor
Potential Vanilloid subfamily member 1 (TRPV1) channels, membrane
receptors involved in pain sensation. Overall, precise and quantitative
delivery of molecules from nanopipettes has been demonstrated, opening
up many applications in biology such as locally stimulating and mapping
receptors on the surface of live cells
Electrochemical Nanoprobes for Single-Cell Analysis
The measurement of key molecules in individual cells with minimal disruption to the biological milieu is the next frontier in single-cell analyses. Nanoscale devices are ideal analytical tools because of their small size and their potential for high spatial and temporal resolution recordings. Here, we report the fabrication of disk-shaped carbon nanoelectrodes whose radius can be precisely tuned within the range 5ā200 nm. The functionalization of the nanoelectrode with platinum allowed the monitoring of oxygen consumption outside and inside a brain slice. Furthermore, we show that nanoelectrodes of this type can be used to impale individual cells to perform electrochemical measurements within the cell with minimal disruption to cell function. These nanoelectrodes can be fabricated combined with scanning ion conductance microscopy probes, which should allow high resolution electrochemical mapping of species on or in living cells