PARTICLE COUNTING, SIZING AND IDENTIFICATION USING NANOELECTRODE ARRAYS
Lead Research Organisation:
University of Cambridge
Department Name: Chemical Engineering and Biotechnology
Abstract
The ability to measure and characterize the shape and composition of particles is an increasingly important aspect of academic research and industrial product development. For example in the development of a new drug, the ability of the body to digest the active chemicals, has been found to be highly dependent upon the structure of the particles which make up the tablet. In our work we are proposing to develop a new approach to analyse particle properties. We will engineer tiny sensors to investigate how particles considerably smaller than the radius of a strand of hair may be identified, sized and their three dimensional shape characterised. The approach will work by passing a current through our new sensor designs. This current is sensitive to particles which come close to the sensor and we will use this characteristic to i) count the number of particles in the system, ii) gain an estimate of the size and distribution of the particles and iii) ultimately investigate the chemical identity of the particles. The particle properties will be analysed using computer models, which will predict the sensor responses to the particle number, size and shape. The results from these models will be used to compare with our experimental studies, allowing the current we measure to be related to the physical properties of the particle.
Organisations
Publications
Gu Y
(2013)
An ac voltammetry approach for the detection of droplets in microfluidic devices
in The Analyst
Liu S
(2008)
The electrochemical detection of droplets in microfluidic devices.
in Lab on a chip
Rees NV
(2009)
A photoelectrochemical method for determining the kinematics of moving particles using an array of individually addressable electrodes.
in Chemistry, an Asian journal
Rees NV
(2008)
Alkali metal reductions of organic molecules: why mediated electron transfer from lithium is faster than direct reduction.
in Journal of the American Chemical Society
Rees NV
(2009)
A photoelectrochemical method for tracking the motion of Daphnia magna in water.
in The Analyst
Sims M
(2010)
Effects of thin-layer diffusion in the electrochemical detection of nicotine on basal plane pyrolytic graphite (BPPG) electrodes modified with layers of multi-walled carbon nanotubes (MWCNT-BPPG)
in Sensors and Actuators B: Chemical
Vuorema A
(2012)
Mesoporous Silica Sputter-Coated onto ITO: Electrochemical Processes, Ion Permeability, and Gold Deposition Through NanoPores
in Electroanalysis
Wiltshire R
(2008)
Channel-Flow Cell for X-ray Absorption Spectroelectrochemistry
in The Journal of Physical Chemistry C
| Description | The target of this programme was the development of generic approaches for the sizing, counting and ultimately identification of particles using electrochemical approaches. The work focused on establishing methods to probe and interface with 'soft matter' type structures with minimal probe-substrate interference. Key developments in the engineering component of this programme include: The development of new numerical models to explore the effects of particle size and shape on the voltammetric response observed at micro- or nano-electrode geometries. The codes developed were also relevant for more traditional macroelectrode structures. The simulations provided new insights into the influence of mass transfer effects around particles ranging in size from sub micron to millimeter dimensions using rapid scan voltammetry as the electrochemical probe. The experimental approach was developed further to address the electrochemical detection of particles and droplets in microfluidic environments. In this application individually addressable nanoelectrode and microelectrode structures were constructed and sited within microengineered channel structures. The voltammetric response was employed for particle counting and velocity measurements. The size and shape of the particles within the channel was also experimentally explored voltammetrically. |
| Exploitation Route | The project is essentially academic in content, so is of relevance to the electrochemical sensing and analysis research community |
| Sectors | Chemicals,Education |
| Description | The monitoring, tracking and analysis of particles within liquid environments is both challenging and of significant impact to a broad range of academic disciplines. A variety of optical microscope methods are currently available and can prove to be powerful analysis tools where good access to the sample for irradiation is available. In this programme we have focused on establishing non-invasive analysis techniques, which can monitor particle trajectories and velocities. |
| First Year Of Impact | 2010 |
| Sector | Education |
| Title | Lattice Boltzmann Modeling of Electrochemical Reactivity |
| Description | Lattice Boltzmann models were developed to simulate the chronoamperometric and cyclic voltammetric response of electrode systems in close proximity to solid particles. The models were used to explore the influence of particle size and position in the observed electrolysis behaviour. |
| Type Of Material | Computer model/algorithm |
| Year Produced | 2008 |
| Provided To Others? | No |
| Description | International Conference on Nanoscience and Nanotechnology |
| Form Of Engagement Activity | Scientific meeting (conference/symposium etc.) |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Participants in your research or patient groups |
| Results and Impact | Conference presentation on the development and application of confluence reactors. |
| Year(s) Of Engagement Activity | 2008 |