A Compact System for Single Ion Channel Recording

The integrated use of ion channels and electronics is a promising approach to develop rapid, sensitive and reliable biosensors able to detect low concentration of target molecules, with applications that range from pharmacology to diagnostic tools. Several reports on stochastic sensors have been published [2-4], however all are based on bulky and expensive instruments. This paper presents a compact (two credit cards size) and low-cost integrated system able to record and process signals in the typical single-channel recording bandwidths. To test the approach, we used signals derived from non-covalent bonds between single alpha-hemolysin pores, embedded into an artificial lipid bilayer, and beta-cyclodextrin molecules. The system is based on a DeltaSigma converter implemented on a PCB using discrete components technology to readout ion currents in the order of pA. The digitized output is sent to a DSP for decimation and filtering and then to a PC for storage, visualization and stochastic data processing.