In this study we are able, using a copper grid substrate, to successfully grow separate nanowires with a high level of crystallinity, for a length of up to 10 mu m. They were synthesized under various temperatures. We compare and contrast three types of geometries (micron-, nano-scale, and tip-like single CuO nanowires), to identify their potential for monitoring the size effects of quantum confinements. The confocal Raman spectrometry results confirm the expected outcome, that reducing of the diameter of a cylindrical cross-section of a single nanowire results in Raman frequency downshifts. The results can be explained by the bond polarizability model. The applicability of investigating the size effects of the quantum confinement of the tip-like geometry of a single nanowire without any preparation for different sizes of nanoparticles is possible because the detection is relatively straightforward and the reproduced Raman signals can be observed. (c) 2008 Elsevier B.V. All rights reserved.