title: Co-ordinated detection of microparticles using tunable resistive pulse sensing and fluorescence spectroscopy.
abstract: Tunable resistive pulse sensing (TRPS) has emerged as a useful tool for particle-by-particle detection and analysis of microparticles and nanoparticles as they pass through a pore in a thin stretchable membrane. We have adapted a TRPS device in order to conduct simultaneous optical measurements of particles passing through the pore. High-resolution fluorescence emission spectra have been recorded for individual 1.9 μm diameter particles at a sampling period of 4.3 ms. These spectra are time-correlated with RPS pulses in a current trace sampled every 20 μs. The flow rate through the pore, controlled by altering the hydrostatic pressure, determines the rate of particle detection. At pressures below 1 kPa, more than 90% of fluorescence and RPS events were matching. At higher pressures, some peaks were missed by the fluorescence technique due to the difference in sampling rates. This technique enhances the particle-by-particle specificity of conventional RPS measurements and could be useful for a range of particle characterization and bioanalysis applications.
authors.affiliation: The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington , P.O. Box 600, Wellington 6140, New Zealand.
authors.forename: Peter
authors.initials: P
authors.lastname: Hauer
authors.affiliation: The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington , P.O. Box 600, Wellington 6140, New Zealand.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Le Ru
authors.forename: Geoff R
authors.initials: GR
authors.lastname: Willmott