Biosensors Nanotechnology

Chapter 4

Impedimetric DNA Biosensors Based on Nanomaterials

Manel del Valle^*,1 and Alessandra Bonanni²

¹Sensors and Biosensors Group, Chemistry Department, Autonomous University of Barcelona, Barcelona, Spain

²Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore

*Corresponding author: [e-mail]

Abstract

This chapter describes variants of DNA sensors (genosensors) that employ electrochemical impedance signal for detecting a target DNA. In this way, the clinical diagnostic-related sought gene or gene variant can be very simply detected with an electrically addressable device, and potentially, without the use of any label. Existing variants for measuring and the different formats for the assay are presented. To improve the performance of these devices, current nanobiotechnology utilizes nanocomponents, either at the transducer level or integrated in the procedure itself, to improve the detection or to amplify the signal. Carbon nanotubes and nanowires, graphene or gold nanoparticles can be used to produce or to modify transducers, fostering their electrical characteristics, or helping in the immobilization of the recognition element. Metal nanoparticles or even quantum dots may be used to improve signal-to-noise ratio. The chapter ends by summarizing existing applications related to clinical diagnostics and discussing the latest trends.

Keywords: DNA biosensor, genosensor, carbon nanotube, ...