Nanofluidic structures for coupled sensing and remediation of toxins

Abstract

One foundational motivation for chemical sensing is that knowledge of the presence and level of a chemical agent informs decisions about treatment of the agent, for example by sequestration, separation or chemical conversion to a less harmful substance. Commonly the sensing and treatment steps are separate. However, the disjoint detection/treatment approach is neither optimal, nor required. Thus, we are investigating how nanostructured architectures can be constructed so that molecular transport (analyte/reagent delivery), chemical sensing (optical or electrochemical) and subsequent treatment can all be coupled in the same physical space during the same translocation event. Chemical sensors that are uniquely well-poised for integration into 3-D micro-/nanofluidic architectures include those based on plasmonics and impedance. Following detection, treatment can be substantially enhanced if mass transport limitations can be overcome. In this context, in situ generation of reactive species within confined geometries, such as nanopores or nanochannels, is of significant interest, because of its potential utility in overcoming mass transport limitations in chemical reactivity. Solvent electrolysis in electrochemically coupled nanochannels supporting electrokinetic flow for the generation of reactive species, can produce arbitrarily tunable quantities of reagents, such as O 2 or H 2 , in situ in close proximity to the site of a hydrogenation catalyst, for example. Semi-quantitative estimates of the local H 2 concentration are obtained by comparing the spatiotemporal fluorescence behavior and current measurements with finite element simulations accounting for electrolysis and subsequent convection and diffusion within the confined geometry. H 2 saturation can easily be achieved at modest overpotentials.

Electrochemical Performance of Micropillar Array Electrodes in Microflows

“…This work provides an applicable guideline for parameters design and structure optimization of the μEDS. In addition, nanochip-based electrochemical detection system (nEDS) with nanoelectrode in nanoflows is one of main research directions recently [ 45 , 46 ], which has the characteristic [ 47 , 48 , 49 , 50 ] of lower reagent consumption, faster analysis time and larger surface-to-volume ratio comparted with μEDS. The presented method in the study can be applied to analyze and optimize the electrochemical performance of nEDS.…”

Development of nano- and microdevices for the next generation of biotechnology, wearables and miniaturized instrumentation

“…The design and manufacturing of devices is today a high-impact research field with consequent impact on other multidisciplinary fields, as well as on the market of chips, 1 nano- and microfluidics technology 2,3 and wearables. 4 To reach the current level of technology it has undergone a long process of development and knowledge creation based on fundamental research.…”