Optical measurements on the nanometer scale

Near-field optics has seen a variety of novel applications, including ultramicroscopy, microspectroscopy, photofabrication, single molecule studies and biochemical sensing. Intracellular calcium responses upon drug stimulation have been monitored in single living cells. Single molecule optical probes have been nanofabricated, and these probe's optical and spectroscopic properties have been characterized. Ultrasensitive detection schemes, using near-field optical probes, have been developed for ultratrace level analysis. Biomolecule immobilization has been carried out on optical fiber probes for the preparation of sensitive biochemical sensors. These research activities will further enrich the field of near-field optics, and it is expected that near field optics' potential will be fully explored for a variety of applications. (C) 1998 Elsevier Science B.V. All rights reserved.