LAUSR

Improving the sensitivity and ultimately the range of particle sizes that can be detected with a single pore extends the versatility of the Coulter counting technique. Here, to enable a pore to have greater sensitivity, we have developed and tested a novel differential resis-tive pulse sensing (DiS) system for sizing particles. To do this the sensor response was generated through a time shift approach utilis-ing a 'self servoing regime' to enable the final signal to operate with a zero background in the absence of particle translocation. The detection and characterisation of a series of polystyrene particles, forced to translocate through a cylindrical glass microchannel (GMC) by a suitable static pressure difference using this approach, is demonstrated. An analytical response, which scales with the size of the particles employed, was verified. Parasitic capacitive effects are discussed, however, translocations on the ms timescale can be detected with high sensitivity and accuracy using the approach de-scribed.