  We present a simplified yet sophisticated variation to localised surface
plasmon resonance spectroscopy, which makes use of naked or non-functionalised,
nanoparticle templates. These nanoparticle templates, produced with a rapid and
scalable process, namely laser annealing, were used as a highly sensitive
surface sensor to monitor the adsorption of both metallic lead and a lead salt
from aqueous solutions, showing a measurable optical response due to a surface
abundance of lead as low as 100 ppm from 0.3 ml of Pb2SO4 solutions, with
concentrations less than 20 ppm. This proposed method enables the end user to
rapidly assess the surface abundance of lead from a simple optical reflectance
measurement and could serve as a platform for in situ analysis within water
filtration and cleaning systems.
