Self Assembly of Arsenic Nanoparticles into Magnetic Nanotubules and Their SERS Activity

Nano-Arsenic are synthesized using Bergenia cilliata roots extracts in water from Arsenic trioxide. The synthesized As nanoparticles, with an average diameter of 13(1) nm, self-assemble into nanotubles with average Feret diameter 530(20) nm. These As nanotubules/nanoparticles have direct band-gap of 2.74 eV and incorporates multiple defect related states. The presence of weak ferromagnetism in these nanotubules/nanoparticles are attributed to the dipolar inertactions amongst the charges on the defect sites. Owing to van derWaals interactions between nanotubules and smaller nanoparticles, nanotubules presents surface roughness which is utilized as surface enhanced raman spectroscopy substrate for probing methylene blue dye with an enhancement factor > 103.