Benito-Lopez, Fernando

Diamond, Dermot

Florea, Larisa

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UNIVERSITY	  COLLEGE	  DUBLIN	  	  	  	  	  	  DUBLIN	  CITY	  UNIVERSITY	  	  	  	  	  	  TYNDALL	  NATIONAL	  INSTITUTE	  	  ADAPTIVE	  POLYMERIC	  MATERIALS:	  	  DEVELOPING	  INTEGRATED	  OPTO-­‐CHEMICAL	  SENSORS	  IN	  MICRO-­‐FLUIDIC	  DEVICES	  INTRODUCTION	  Polymer	  brush	  coa?ngs	  containing	  the	  photochromic	  molecule,	  spiropyran,	  or	  the	  conduc?ng	  polymer,	  polyaniline,	  were	  synthesised	  on	  the	  interior	  of	  micro-­‐capillaries	  and	  micro-­‐ﬂuidic	  channels	  using	  the	  “graLing	  from”	  approach.	  Due	  to	  their	  switchable	  sensing	  capabili?es,	  these	  coa?ngs	  can	  be	  successfully	  used	  for	  metal	  ion-­‐	  and	  pH-­‐	  sensing,	  respec?vely,	  in	  con?nuous	  ﬂow	  mode.	  Larisa	  Florea,	  Dermot	  Diamond,	  Fernando	  Benito-­‐Lopez	  The	  photocromism	  of	  spiropyrans	  is	  due	  to	  photocleavage	  of	  the	  C–O	  spiro-­‐bond	  of	  the	  colourless	  spiropyran	  (SP)	  upon	  UV	  irradia?on,	   producing	   the	   coloured	   merocyanine	   (MC)	   that	  can	  return	  to	  the	  SP	  form	  by	  ring	  closing	  under	  visible	  light.	  	  SPIROPYRAN-­‐BASED	  COATINGS	  METAL	  IONS	  SENSING	   pH	  SENSING	  NRO NO2 NR+VISUVONO2_SP MCSpiropyran	   based	   coa?ngs	   were	   obtained	   in	   the	   interior	   of	  fused-­‐silica	  micro-­‐capillaries	   (100	  µm	   I.D.)	  using	   ring-­‐opening	  metathesis	  polymerisa?on	  of	  an	  appropriate	  spiro-­‐monomer.	  The	   coa?ngs	   obtained	   are	   covalently	   aYached	   to	   the	   inner	  wall	   of	   the	   micro-­‐capillary	   and	   inherit	   the	   photocromic	  proprie?es	  of	  the	  spiropyran,	  showing	  no	  photobleaching.	  	  365 µm 100 µm + Co2+  + Ni2+  + Cu2+  + Zn2+  + Cd2+  UV VIS Absorbance @ 563 nm (a.u) 365 µm 100 µm The	   open	   MC	   form	   exibits	   par?cular	   metal	   ion	   binding	  proprie?es	   -­‐	   this	   behaviour	   is	   not	   manifested	   by	   the	   closed	  spiropyran	   form.	   Photoswitchable	   coa?ngs	   based	   on	  spiropyran	   can	   be	   used	   to	   photo-­‐detect	   divalent	   metal	   ions	  solu?ons	  when	  passing	  through	  the	  capillary.	  	  Polyaniline	   (PAni)	   is	   an	   example	   of	   a	   conduc?ng	   polymer	   whose	  proper?es	  (op?cal/electrical)	  change	  in	  response	  to	  varia?ons	  in	  the	  immediate	  environment	  of	   the	  material.	  The	  emeraldine	  base	   form	  (blue)	  can	  be	  reversibly	  doped	  with	  acidic	  species	  to	  the	  emeraldine	  salt	  (green).	  This	  property	  makes	  polyaniline	  coa?ngs	  a	  new	  tool	  for	  the	  developing	  of	  op?cal	  pH	  sensors.	  	  	  POLYANILINE-­‐BASED	  COATINGS	  Using	   the	   “graLing	   from”	   approach,	   polyaniline	   nanoﬁbres,	  covalently	  aYached	  to	  the	  inner	  wall	  of	  the	  micro-­‐ﬂuidic	  channel	  are	  obtained.	  Their	  nano-­‐conﬁgura?on	  ensures	  short	  diﬀusion	  paths	  and	  therefore	  fast	  response	  ?mes.	  50 µm - 1000µm  2 mm UV–Vis	   	  spectra	  of	  PAni	  coa?ngs	   are	   measured	  for	   each	   pH	   solu?ons	  that	   is	   passed	   through	  the	  channel.	  Moreover,	  the	   PAni	   coa?ngs	   have	  the	   ability	   of	   sensing	  pH	  gradients	  induced	  in	  the	  micro-­‐channel.	  Emeraldine Salt Emeraldine Base Acknowledgements:	  Irish	  Research	  Council	  for	  Science,	  Engineering	  and	  Technology	  (IRCSET)	  -­‐	  Embark	  Ini?a?ve	  ,	  Science	  Founda?on	  Ireland	  under	  CLARITY	  	  grant	  07/CE/I1147	  	  

Adaptive polymeric materials: developing integrated opto-chemical sensors in micro-fluidic devices

http://doras.dcu.ie/17452/1/Poster_clarity_Larisa_fbl.pdf

Adaptive polymeric materials: developing integrated opto-chemical sensors in micro-fluidic devices

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