Nanoliter-scale, regenerable ion sensor: sensing with surface functionalized microstructured optical fiber

The first nanoliter-scale regenerable ion sensor based on microstructured optical fiber (MOF) is reported. The air holes of the MOF are functionalized with a monoazacrown bearing spiropyran to give a switchable sensor that detects lithium ions down to 100 nM in nanoliter-scale volumes. Ion binding is turned on and off on upon irradiation with light, with the sensor being unaffected by multiple rounds of photoswitching. Unbound ions are flushed from the fiber in the ‘off’ state to allow the sensor to be reused. The integration of an ionophore into the sensor paves the way for the development of highly specific light-based sensing platforms that are readily adaptable to sense a particular ion simply by altering the ionophore design.

[1]  B. Lukyanov,et al.  Spiropyrans: Synthesis, Properties, and Application , 2006 .

[2]  F. Raymo,et al.  Synthesis and properties of benzophenone-spiropyran and naphthalene-spiropyran conjugates. , 2007, The Journal of organic chemistry.

[3]  Stephen C Warren-Smith,et al.  Suspended nanowires: fabrication, design and characterization of fibers with nanoscale cores. , 2009, Optics express.

[4]  Tanya M. Monro,et al.  Sensing in suspended-core optical fibers , 2011, IEEE Winter Topicals 2011.

[5]  Tanya M. Monro,et al.  Photoinduced Electron Transfer Based Ion Sensing within an Optical Fiber , 2011, Sensors.

[6]  Tanya M. Monro,et al.  Fluorescence-based aluminum ion sensing using a surface-functionalized microstructured optical fiber. , 2011, Langmuir : the ACS journal of surfaces and colloids.

[7]  S. Filetti,et al.  Early diagnosis of medullary thyroid carcinoma: is systematic calcitonin screening appropriate in patients with nodular thyroid disease? , 2011, The oncologist.

[8]  David J. Richardson,et al.  Sensing with microstructured optical fibres , 2001 .

[9]  Byoungho Lee,et al.  Current status of micro- and nano-structured optical fiber sensors , 2009 .

[10]  Dermot Diamond,et al.  Photo-regenerable surface with potential for optical sensing , 2006 .

[11]  Garry Berkovic,et al.  Spiropyrans and Spirooxazines for Memories and Switches , 2000 .

[12]  C. Orvig,et al.  Boon and Bane of Metal Ions in Medicine , 2003, Science.

[13]  R. Sauerbrey,et al.  Coupling of high-power UV laser radiation into fused silica fibers using pressurized gases. , 1988, Applied optics.

[14]  Tanya M. Monro,et al.  Driving down the Detection Limit in Microstructured Fiber-Based Chemical Dip Sensors , 2011, Sensors.

[15]  I. Willner,et al.  Light-controlled electron transfer reactions at photoisomerizable monolayer electrodes by means of electrostatic interactions: active interfaces for the amperometric transduction of recorded optical signals , 1997 .

[16]  Daisuke Watanabe,et al.  Colorimetric sensing of metal ions by bis(spiropyran) podands: Towards naked-eye detection of alkaline earth metal ions , 2009 .

[17]  K. Kimura,et al.  Effect of photoirradiation on chromatographic separation of alkali metal ions using crowned-spirobenzopyran-immobilized silica , 2012 .

[18]  H. Ebendorff-Heidepriem,et al.  Antibody immobilization within glass microstructured fibers: a route to sensitive and selective biosensors , 2008, International Conference on Optical Fibre Sensors.

[19]  Stephen C Warren-Smith,et al.  Fluorescence-based sensing with optical nanowires: a generalized model and experimental validation. , 2010, Optics express.

[20]  Tomoaki Nakamura,et al.  Functionalization on silica gel with allylsilanes. A new method of covalent attachment of organic functional groups on silica gel. , 2003, Journal of the American Chemical Society.

[21]  K. Kamada,et al.  Decisive Factors in the Photoisomerization Behavior of Crowned Spirobenzopyrans: Metal Ion Interaction with Crown Ether and Phenolate Anion Moieties , 2002 .

[22]  B. Ocko,et al.  Postassembly chemical modification of a highly ordered organosilane multilayer: new insights into the structure, bonding, and dynamics of self-assembling silane monolayers. , 2008, ACS nano.

[23]  A. Knoesen,et al.  Reversible Low-Light Induced Photoswitching of Crowned Spiropyran-DO3A Complexed with Gadolinium(III) Ions , 2012, Molecules.

[24]  Yasuhiro Shiraishi,et al.  Thermoresponsive copolymer containing a coumarin-spiropyran conjugate: reusable fluorescent sensor for cyanide anion detection in water. , 2011, ACS applied materials & interfaces.

[25]  Jason Locklin,et al.  Fabrication of spiropyran-containing thin film sensors used for the simultaneous identification of multiple metal ions. , 2011, Langmuir : the ACS journal of surfaces and colloids.

[26]  S. Giordani,et al.  Molecular switches as photocontrollable "smart" receptors. , 2012, Chemical Society reviews.

[27]  Stephen C Warren-Smith,et al.  Enhanced fluorescence sensing using microstructured optical fibers: a comparison of forward and backward collection modes. , 2008, Optics letters.

[28]  Shiguo Zhang,et al.  Photochromism of spiropyran in ionic liquids: enhanced fluorescence and delayed thermal reversion. , 2009, The journal of physical chemistry. B.

[29]  D. Diamond,et al.  Photoswitchable stationary phase based on packed spiropyran functionalized silica microbeads , 2009 .

[30]  D Meschede,et al.  Switching photochromic molecules adsorbed on optical microfibres. , 2012, Optics express.

[31]  K. Kawamura.  In situ UV-VIS detection of hydrothermal reactions using fused-silica capillary tubing within 0.08-3.2 s at high temperatures. , 2002, Analytical Sciences.

[32]  Yong-mei Wang,et al.  Synthesis and Photochromism of Photochromic Spiro Compounds Having a Reactive Pendant Group. , 2002 .

[33]  T. Becker,et al.  Gas-kinetic interactions of nitrous oxides with SnO2 surfaces , 1998 .

[34]  Tanya M. Monro,et al.  Silica exposed-core microstructured optical fibers , 2012 .