Fundamental building blocks for molecular biowire based forward error-correctingbiosensors

Abstract

This paper describes the fabrication, characterization and modeling of fundamental logicgates that can be used for designing biosensors with embedded forward error-correction(FEC). The proposed logic gates (AND and OR) are constructed by patterning antibodiesat different spatial locations along the substrate of a lateral flow immunosensor assay. Thelogic gates operate by converting binding events between an antigen and an antibodyinto a measurable electrical signal using polyaniline nanowires as the transducer.In this study, B. cereus and E. coli have been chosen as model pathogens. Thefunctionality of the AND and OR logic gates has been validated using conductancemeasurements with different pathogen concentrations. Experimental results showthat the change in conductance across the gates can be modeled as a log-linearresponse with respect to varying pathogen concentration. Equivalent circuitsmodels for AND and OR logic gates have been derived based on measured results.