Effect of the ionic-strength of the gating-solution on a bioelectronic response

Bioelectronic organic transistors have been recently proposed as a disruptive wide-field label-free single-molecule biosensing technology. Key relevant for this millimetric sized electrolyte-gated field-effect-transistor is a self-assembled-monolayer attached to the gate comprising a highly-packed layer of recognition elements. Here a dedicated study of the FET sensing response as a function of the salinity of the electrolyte solution is proposed. It has been demonstrated that the device response is dramatically reduced at high ionic strength and this offer the rationale for choosing to operate the device in pure water where the Debye length, λ D , is 100 nm.