a plug in chip the chip may further be made to act like an array with a different surface molecule for detection of different bio molecules application_number US 61458006 A description developed is an electrical method for testing biosensors electrical measurement of binding biological pairs is difficult many biosensors rely on an exchange of electrons during the reaction this exchange of electrons oxidation or reduction of the analyte can be read as a change in resistance or current through the sensor the problem with most biological reactions is the lack of electron transfer in the reaction there are no electrons to be measured by conventional conductivity methods most biological pairs bond together via weak electrostatic forces examples of these pairs are dna rna and antibody antigen pairs to circumvent the problem of a lack of electron transfer in these antibody antigen based biological systems focus must be on the type of bonding the electrostatic forces that hold these bio pairs together are usually hydrogen bonding and electrostatic interactions both of these have a characteristic shift in electron density near the bonding site without a transfer of electrons this transfer of electron density can be thought of as a dielectric shift the shift in dielectric potential can be measured as a change in capacitance advantage of this capacitance shift is taken to create an electrical measurement where it was once not possible prior art has shown other measurements of capacitance for bio sensing nearly all methods use impedence spectroscopy pei et al u201c amplification of antigen antibody interactions based on biotin labeled protein streptavidin network complex using impedance spectroscopy u201d biosensors amp bioelectronics 2001 355 361 jina gou guan et al u201c impedimetric biosensors u201d journal of bioscience and bioengineering.