Not nano enough. To change one element into another you have to change the number of protons in the nucleus. If you just take away an electron, you get an ion of the same element. You might one day see nanobots weaving polymers or assembling DNA strands, but alchemy seems remote. By the way, a true form of alchemy already exists.
Nuclear reactors change elements into other elements simply by adding neutrons to their nuclei.
The initial result is usually unstable and decays to some other element which usually is also unstable, and so on until a stable nucleus remains. Actually, elements can be converted into different elements by normal radioactive decay and by induced processes in nuclear reactors and particle accelerators. Hello, To do alchemy, as we know it today, you would have to manipulate the number of proton and neutrons in the nucleus of an atom and the electrons in the atom's shells. Nanotechnology can move molecules around but it cannot manipulate what is inside of an atom. In other words, it cannot change the nature of an atom.