Biological sensing with an on-chip resistive pulse analyzer

Resistive pulse sensors (or Coulter counters) detect the conductance change caused by single fluid-borne particles transiting a pore. Their simplicity in design and use, along with their capability for single-molecule sensitivity, make them well-suited to the analysis of biological particles. Here, we use standard methods of micro- and nanolithography to construct resistive-pulse devices that combine microfluidics with electronic sensing. We use the devices to detect single latex colloids, single DNA molecules, and specific antibody/antigen binding. We discuss the advantages of our design, and prospects for future applications.