Anodizing aluminum creates aluminum oxide - a pretty good insulator. So while you may achieve a narrow oxide line, there'd be no carriers in it and you wouldn't have a "nanowire." It is possible, but VERY difficult to plate aluminum - the material loves to form an oxide! So the films produced this way tend to have high sheet resistivity. Also, you can create an oxide "shell" around the core aluminum line by anodizing. The metal core dimensions would shrink on anodizing (while the oxide film expands.)
Growing long nanowires via electrodeposition is difficult. trying that with ZnO nanowires the highest array was about 3.5um. However, using hydrothermal method with the assistance of polymers like PEI the length of the array reached 50um.
Please have a look at our paper "Superconducting properties of lead nanowires fabricated by electrochemical deposition" https://www.researchgate.net/publication/229379639_Superconducting_properties_of_lead_nanowires_fabricated_by_electrochemical_deposition?fulltextDialog=true&ev=prf_pub_xaddfulltext
The fabrication technique is well described in the paper. However, if you have any specific questions, please feel free to ask.
Good luck,
Article Superconducting properties of lead nanowires fabricated by e...
you can get detail of making nano wire with coating you would ask this question from a Sahand university proffeser "Farzad Nasirpouri" he has a PhD student that he works on making nanowire
For the growth of longer nanowires in AAO, you must have grow AAO with long thickness. I have grown nanowires in micrometer range in AAO using AC electrodeposition. You can check my papers from net or give me ur email address, I will send that to you. If you have any question plz feel free