Integrating biological molecules with electrode surfaces for bioanalytical sensing applications

A detection scheme for Anthrax toxins based on the interaction of an ion channel formed by protective antigen 63 (PA63)7, a heptameric ion channel forming toxin, with lethal factor is demonstrated.To prepare a sensor, a biomimetic membrane is formed on an electrode surface through a thiolipid molecule with a custom synthesized poly(ethylene oxide) spacer. Thus a membrane is formed across the electrode with an aqueous space of ~ 2 nm. The high-specificity of the TF-(PA6 3)7 interaction enables the detection of Anthrax proteins on the order of pmol/L. In addition to highly sensitive detectors, this tethered membrane construct is scaleable and can be extended to devices with micron and sub-micron sensing pads, critical for the miniaturization required for novel bioelectronic devices.