Impedimetric immunosensor for the detection of histamine based on reduced graphene oxide

In this work, we present a reduced graphene oxide-based impedimetric histamine biosensor. Histamine as a bioamine mediates immune-modulatory effects in acute inflammatory and allergic reactions. In a proof-of-principle approach, the low-cost sensor platform determines low concentrations of histamine in buffer solution with an impedimetric readout technique. As a sensor platform we used ultra-thin graphene oxide lines fabricated by a simple soft-lithographic approach. The lines of about 20m width were characterised by atomic force microscopy and scanning electron microscopy. Reduction of graphene oxide to a conductive transducer material was performed by a rapid thermal protocol in inert atmosphere. The reduction process was monitored by impedance spectroscopy and X-ray photoelectron spectroscopy. For our biosensor experiments we adopted a commonly-used protocol for surface plasmon resonance (SPR) detection of histamine. With our reduced graphene oxide platform we detected antigen-antibody binding events of histamine with concentrations of 0.1-1M via impedance changes in a low frequency range. The results from the rGO sensors were comparable to the SPR detection.