ABSTRACT
A holistic perspective of physical, chemical and biological nanosensors is sketched. In this all-inclusive view, the milestones reached in mechanical, thermal, optical, magnetic, chemical and bio-nanosensors are traced besides the two foundation tools of nanotechnology, viz., STM and AFM. As opposed to the scientific classification of nanosensors into physical, chemical and biological domains, no less important is the classification from applications viewpoint because the nanosensors are to be put at the service of mankind. The main research area that comes to the forefront is devising ways and means to prevent degradation of bio-nanosensors by ageing phenomena, to supply nanoliters of sample to nanosensors for testing, to harvest energy from the environment to operate nanosensors without batteries and to build networks of nanosensors without wires. Innovative research work in these directions will prove to be a boon by bringing enormous improvements in our everyday life.
