2 research outputs found
In Situ Electrochemical ELISA for Specific Identification of Captured Cancer Cells
Circulating tumor cells (CTCs) are
cancer cells disseminated from a tumor into the bloodstream. Their
presence in patient blood samples has been associated with metastatic
disease. Here, we report a simple system that enables the isolation
and detection of these rare cancer cells. By developing a sensitive
electrochemical ELISA method integrated within a microfluidic cell
capture system, were we able to reliably detect very low levels of
cancer cells in whole blood. Our results indicate that the new system
provides the clinically relevant specificity and sensitivity needed
for a convenient, point-of-need assay for cancer cell counting
High-Density Nanosharp Microstructures Enable Efficient CO<sub>2</sub> Electroreduction
Conversion of CO<sub>2</sub> to CO
powered by renewable electricity not only reduces CO<sub>2</sub> pollution
but also is a means to store renewable energy via chemical production
of fuels from CO. However, the kinetics of this reaction are slow
due its large energetic barrier. We have recently reported CO<sub>2</sub> reduction that is considerably enhanced via local electric
field concentration at the tips of sharp gold nanostructures. The
high local electric field enhances CO<sub>2</sub> concentration at
the catalytic active sites, lowering the activation barrier. Here
we engineer the nucleation and growth of next-generation Au nanostructures.
The electroplating overpotential was manipulated to generate an appreciably
increased density of honed nanoneedles. Using this approach, we report
the first application of sequential electrodeposition to increase
the density of sharp tips in CO<sub>2</sub> electroreduction. Selective
regions of the primary nanoneedles are passivated using a thiol SAM
(self-assembled monolayer), and then growth is concentrated atop the
uncovered high-energy planes, providing new nucleation sites that
ultimately lead to an increase in the density of the nanosharp structures.
The two-step process leads to a new record in CO<sub>2</sub> to CO
reduction, with a geometric current density of 38 mA/cm<sup>2</sup> at −0.4 V (vs reversible hydrogen electrode), and a 15-fold
improvement over the best prior reports of electrochemical surface
area (ECSA) normalized current density