Table 2.

Examples of nanosensors and their characteristics.

Nanoscale Sensor Material	Context	Common Analytes	Performance
Dye-functionalized nanostructures79–83	mostly in vitro and in cells some in vivo examples	nucleic acid sequences - including single-base mutations proteins enzymes	strong sensitivity signal amplification subject to false positives/negatives light penetration into biological specimens dependent on the dye
Carbon nanostructures84–87,89–94	in vitro in cells in vivo	small molecules proteins DNA/RNA	Single-molecule sensitivity signal penetration into tissues multiplexing specialized instrumentation often needed
Silicon nanowires88	primarily in vitro	ions/pH proteins nucleic acids	very high sensitivity usually requires electrical contacts preventing use within cells
Quantum dots/silica nanoparticles58,59,61,62	in cells in vivo	ions/pH	bright signals subject to potential biocompatibility/toxicity issues