NOVELTY - A nanowire assembly method comprises optically trapping a semiconductor nanowire with an infrared single-beam optical trap and attaching the nanowire to an organic or inorganic structure by laser fusing. The nanowire is further trapped in a fluid environment. The optical trap has a beam wavelength of 1064 nm. The nanowire has an aspect ratio greater than 100 and a diameter less than 100 (preferably less than 80) nm. The nanowire and the organic or inorganic structure form a heterostructure. USE - For fabricating a nanowire assembly for use as e.g. active photonic devices, passive photonic devices, optical probes, subwavelength microscopy. ADVANTAGE - Nanowires with diameters as small as 20 nm and aspect ratios of above one hundred can be trapped and transported in three dimensions, enabling the construction of nanowire architectures which may function in various capacities. Nanowire structures can now be assembled in physiological environments, offering new forms of chemical, mechanical and optical stimulation of living cells. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a nanowire assembly comprising a nanowire and an organic or inorganic structure or an arbitrary structure. DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of an optical tweezers instrument for nanowire trapping.