Why can nanowire sensors detect very small amounts of chemicals or biological agents?

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electron hole: movement — materials science Movement of an electron hole in a crystal lattice.

Nanowire sensors are highly effective at detecting trace amounts of chemicals or biological agents primarily due to their high surface-to-volume ratio.1

Because these nanostructures have such small dimensions—typically with a diameter of 100 nanometers or less—a significantly larger proportion of their atoms are located on the surface rather than within the interior of the wire. This structural characteristic drastically enhances the material's chemical reactivity and physical sensitivity, allowing surface interactions to play a dominant role in sensing applications.1

When target molecules interact with the surface of a nanowire, the resulting changes in properties—such as electrical conductivity—are easily detected, even when only a few molecules are present. This sensitivity makes them ideal for advanced applications in biotechnology, including biodetection and the development of highly precise biomedical sensors.1