03334nas a2200265 a 450000500170000000800410001703500150005810000250007324500720009826000670017030000190023749000270025650001650028350200580044852022060050665000300271265000170274265000180275970000330277770000500281070000440286071000390290481000590294385600660300220260818090456.0110309s2008    th uu|m rtt   0|  a1eng d  a.b120916010 aSiriphun Ameritachot10aDeveloping a plasmon resonance sensor for heavy metal ion detection  aPathum Thani, Thailand :bAsian Institute of Technology,c2008  a57 p. :billl.1 aThesis ;vno. ME-08-02  aA thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Microelectronics,  School of Engineering and Technology  aThesis (M.Eng.) - Asian Institute of Technology, 2008  aHeavy  metals  are  widely  used  in  many  industr ial  fields,  for  example,  copper  is  used  as   conductor   in   electronic   devices   that   is    causing   increasing   environmental   concerns.    Nanotechnology  is  a  promising  discipline  that  shows  promise  to  impact  diverse  fields   including  metal  sensors.  In  order  to  test  heavy  metal  contaminants  in  water,  we  report  a   novel   strategy   for   using   nanoparticles   cappe d   with   polymers   (chitosan,   crosslinked    chitosan,   Poly   Acrylic   Acid   (PAA),   Poly    sodium   Styrene   Sulfonate   (PSS)   and    glutaraldehyde) for sensing the metal ions. Th e nearly monodispensed nanoparticle of gold  was used for the metal ion sensing whic h were obtained by reducing 1 mM of HAuCl 4  with  tri sodium citrate in 1:3 ratio.  The  polycationic  nature  of  polymers  utilized   for  sensing  heavy  metal  ions  enables   attachment  of  negatively  charged  nanoparticles  onto  the  polymers  through  electrostatic   interactions.  Use  of  polymer  serves  dual  pur pose  of  providing  sufficient  steric  hindrance   ensuring stability of the colloid and also the  functionalization of gold the nanoparticles for  sensing.  The  well-documented  chelating  proper ties  of  chitosan  and  the  sensitivity  of  the   plasmon  resonance  in  gold  nanoparticles  to  agglomeration  have  been  employed  to  detect   low concentrations of heavy metals ions in  water. A comparison of the optical absorption  spectra  of  the  colloidal  suspension  before   and  after  exposure  to  metal  ions  is  a  good   indicator of the concentration of the heavy meta l ions. In order to complete the chelation of  the  metal  ions,  about  1  hour  was  sufficient  for   the  reaction  in  most  of  the  cases,  but  for   0.5%  PSS  capped  gold  colloids,  the  reaction  wa s  completed  within  5  {u2013}  10  minutes.  The   best sensitivity for copper ion, obtained from  the optical sensors, is 200 ppb by using gold  colloid capped 0.1% glutaraldehyde crosslinked  chitosan. This simple metal ion sensor can  be implanted in lab-on-chip type of applications for easier implementation. 0aSurface plasmon resonance 0aHeavy metals 0aNanoparticles1 aDutta, Joydeep,eChairperson1 aAfzulpurkar, Nitin V.,eExamination Committee1 aShipin, Oleg V.,eExamination Committee2 aRTG Fellowship,eScholarship donor2 aAsian Institute of Technology.tThesis ;vno. ME-08-02  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B03431