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A sol–gel derived AgCl photochromic coating on glass for SERS chemical sensor applicati

A sol–gel derived AgCl photochromic coating on glass for SERS chemical sensor applicati
A sol–gel derived AgCl photochromic coating on glass for SERS chemical sensor applicati

Sensors and Actuators B106(2005)

660–667

A sol–gel derived AgCl photochromic coating on glass for

SERS chemical sensor application

M¨u rvet V olkan b,David L.Stokes a,?,Tuan V o-Dinh a

a Advanced Biomedical Science and Technology Group,Oak Ridge National Laboratory,P.O.Box2008,Oak Ridge,TN37831-6101,USA

b Department of Chemistry,Middle East Technical University,06531Ankara,Turkey

Received25February2004;received in revised form14September2004;accepted15September2004

Available online28October2004

Abstract

A new optically translucent material has been prepared that acts as a substrate for surface-enhanced Raman spectroscopy.This material is a silica matrix,synthesized by the sol–gel method and containing in situ precipitated AgCl particles which serve as precursors for nanoparticles of elemental silver.Reduction of AgCl to silver nanoparticles is achieved by UV irradiation.The SERS-active medium was distributed on glass supports(cover glass slips,0.5mm thick),hence producing thin,sturdy,and optically translucent substrates.SERS activity was evaluated by using brilliant cresyl blue and1-aminopyrene as model compounds.Parameters including the sol–gel composition,the aging period of the sol–gel,and the UV exposure time for photoreduction of the SERS medium were thoroughly investigated.These new substrates have exhibited long shelf lives;furthermore,they can be easily regenerated through a redox cycle involving chemical oxidation and photoreduction steps.In addition to use in direct chemical analysis,this novel type of SERS substrate can be used for indirect monitoring of HNO3acid vapor via measurement of the SERS signal of1-aminoyrene,which is attenuated as the substrate is oxidized by the acid vapor.

?2004Elsevier B.V.All rights reserved.

Keywords:Raman;SERS substrate;Sol–gel;Photochromic;HNO3

1.Introduction

Since its discovery,surface-enhanced Raman spec-troscopy(SERS)[1]has been extensively studied[2–4].In general,the observation of the SERS effect requires the pres-ence of small metal particles or rough surfaces of conductive material[4–7].Despite numerous successful applications,ac-ceptance of SERS as a practical analytical technique has thus far been limited,due largely to the lack of commercially available and analytically suitable substrates[4].Notwith-standing,exhaustive efforts have been devoted towards the development of practical substrates in order to investigate and utilize the SERS effect.Results of these efforts have in-cluded studies with silver particles on quartz posts[8],metal island?lms[9,10]self-assembled monolayer-modi?ed silver ?Corresponding author.Tel.:+17034905292;fax:+17034905293.

E-mail address:dstokes547@https://www.wendangku.net/doc/09988306.html,(D.L.Stokes).substrates[11],etched metal surfaces[12],extraction mem-branes[13],silver electrodes[14],metal-coated microsphere-based substrates[15],photographic paper[16],and powdered silver[17].Each of the methods mentioned for the generation of SERS-active surfaces has its advantages and limitations. No particular surface meets the needs of all areas of SERS studies.Hence there is still room for improvement and opti-mization of SERS-active surfaces.The ideal substrate should be easy to prepare,inexpensive,and sturdy enough for?eld application.

One type of medium which may address many of these factors of practicality is based on a sol–gel matrix.Sol–gel is prepared by the hydrolysis and polycondensation of tetra-alkoxysilanes.The use of alkyl or aryl derivatives of tetra-alkoxysilanes as precursors can produce a crack-free thin surface coating[18].The most extensively used derivative precursor for preparation of organically modi?ed silica is methyl triethoxysilane,MTEOS[19].Sol–gel materials of-

0925-4005/$–see front matter?2004Elsevier B.V.All rights reserved. doi:10.1016/j.snb.2004.09.019

M.Volkan et al./Sensors and Actuators B106(2005)660–667661

fer a unique environment for stabilizing metal colloids for SERS applications because they are transparent in the visi-ble spectral region,and are physically and chemically stable [20,21].

Photochromism is de?ned as reversible light-induced color change of a material.Photochromic glasses containing silver halides show a strong and reversible darkening upon irradiation with UV light due to the reduction of silver halide to silver metal aggregates.Reversibility implies that there is no loss of reaction product from the reaction zone and that the silver and halogen can return to their original states after bleaching[22].In order to use photochromic glass as a re-generable SERS substrate,the UV radiated substrate should be SERS-active and this activity should not be diminished after several darkening and bleaching cycles.

The preparation of photochromic sol–gel glasses is of par-ticular interest.As recently shown by Zayat et al.[23,24], it is possible to incorporate AgCl crystals in sol–gel silica ?lms which serve as precursors for embedded nanoparticles of silver.The?lms show photochromic behavior by darken-ing upon irradiation with UV light,indicating formation of Ag particles on the surface.Furthermore,the substrate can be completely bleached upon exposure to HNO3vapor,thereby returning the substrate to the non-reduced state.

Using these properties as motivation for the develop-ment of a more practical substrate,we distributed a thin ?lm of a sol–gel-derived AgCl photochromic medium on glass supports.These non-reduced substrates were reduced to the SERS-active state via irradiation with UV light(be-low350nm).SERS activity was then evaluated by monitor-ing the signal from a model compound,brilliant cresyl blue, in several parameter optimization studies.Furthermore,1-aminopyrene was used as a model compound to illustrate the usefulness of this novel type of SERS substrate for direct chemical analysis and indirect HNO3acid vapor monitoring.

2.Experimental

2.1.Chemicals

All chemicals were used as purchased.Test compounds included brilliant cresyl blue(BCB)(Allied Chemical and Dye Corp),1-aminopyrene(1-AP)(Aldrich).All solutions were prepared in reagent-grade ethanol(Aaper Alcohol and Chemical Co.).

2.2.Preparation of substrates

The preparation of the coatings and processing of pho-tochromic SERS-active layers is shown in Fig.1.The sol was prepared by mixing1.3mL TEOS,0.3mL MTEOS,5.3mL ethanol,0.8mL water and0.03mL concentrated HNO3. At the end of the exothermic reaction(approximately1h), 1.5mL of4M AgNO3and0.5mL of4M trichloroacetic acid(TCAA)were added to the mixture.The?nal sol–gel

was Fig.1.Preparation of SERS substrates.Precursors:TEOS,MTEOS,Et-OH, H2O.

spin-coated on glass plates(20mm×8mm),which had been previously washed and stored in reagent-grade MeOH.The gel-coated plates were left overnight at room temperature. Shortly before being used in SERS measurements,the plates were UV-irradiated in a photochemical reactor(The South-ern New England Ultraviolet Company,Model rpr-100)for 10min and heated in an oven at60?C for1h.Unless speci?ed by the text,the irradiation step preceded the heating step.The coatings darkened upon exposure to UV light,indicating the reduction of silver ions to silver nanoparticles.The SERS ac-tivity of the surface can be lost in storage due to air oxidation of silver particles.In order to reactivate the surface,deacti-vated substrates were?rst brie?y(3s)subjected to the vapor of boiling concentrated HNO3until the dark color became bleached,and then re-irradiated with UV light.

2.3.Instrumentation

Fig.2illustrates the detection system used in these studies. SERS spectra were acquired with a HR-320spectrograph(SA Instruments,Inc.)The excitation radiation was the632.8nm line of a helium–neon laser(Spectra Physics,Model106-1). The beam was focused down to a diameter of~100?m at the sample,and the Raman-scattered radiation was collected at180?with respect to the excitation beam using a two-lens system.This“backside”substrate excitation geometry was possible due to the translucent nature of the SERS substrate.A holographic notch?lter(Physical Optics Corp.)was placed in the collected beam to reject the unwanted Rayleigh scattering. The Raman radiation was focused onto a600?m diameter quartz optical?ber(General Fiber Optics),which transmitted the collected signal to the spectrograph.

2.4.Vapor exposure studies

A20.0mL open glass scintillation vial containing0.5mL of concentrated HNO3,and three photochromic substrates spiked with1×10?3M1-AP were placed in a500mL plastic container.A spacer was used to elevate the substrates

662M.Volkan et al./Sensors and Actuators B 106(2005)

660–667

Fig.2.Schematic diagram of SERS detection system.

from the bottom of the container,preventing contact with any acid possibly condensed and collected at the bottom of the container.A separate 500mL container was used for each time interval to be measured.The containers were sealed.The substrates were removed from respective containers after 10,20,30,and 60min of exposure.The 1-AP SERS spec-tra yielded by the exposed substrates were acquired imme-diately after removal of substrates from the acid exposure vials.

3.Results and discussion

There are numerous factors that may affect the surface enhancement performance of the new photochromic sol–gel-based substrates presented in this work.These factors in-clude the composition of the sol,the sol–gel gelation and ag-ing periods,and the photoreduction irradiation period.The SERS spectra of BCB and 1-AP were used as direct indica-tors for the successful photodeposition of the SERS-active silver nanoparticles.

The precipitation of silver chloride particles in situ was achieved by the reaction of silver nitrate with TCAA.In order to preserve the photochromic behavior,the sol–gel composition reported for the preparation of reversible pho-tochromic glasses [24]was modi?ed slightly.The concentra-tions of AgNO 3and TCAA were increased to enhance the surface plasmon resonance effect while maintaining the rec-ommended 1:1ratio [24]of silver to chloride.The volume of MTEOS used was diminished to facilitate the develop-ment of a more polar surface.These optimization studies were carried out under acid-catalyzed conditions.The gel composition that generated the smooth coating,which re-sulted in the greatest subsequent SERS activity for the model compounds,was selected.It is well known that the acidity of the medium is an important factor that affects the struc-ture of the ?nal gel [25].Hence base-catalyzed conditions were also explored in this work by adding 0.1mL concen-trated NaOH to 10mL of the sol.The spectra of 10?5M BCB obtained with the substrates coated with optimized sol–gel composition at acidic and basic conditions are given in Fig.3.Both types of coatings yielded spectra with the

M.Volkan et al./Sensors and Actuators B106(2005)660–667

663

Fig.3.The effect of the sol–gel structure on the SERS signal:SERS spectra of10?5M BCB on substrates coated with(a)acidic sol–gel and(b)basic sol–gel. He–Ne laser power was8mW at632.8nm.

model compound;however,the sensitivity obtained with the acidic sol–gel was much higher than that of the basic sol–gel. Hence,the acidic sol–gel procedure was adopted for substrate preparation.

For the purpose of this discussion,aging of a gel is de?ned as the immersion of a cast object in liquid for a given period of time.The strength of the sol–gel was expected to increase with aging time due to the continued polycondensation

and Fig.4.The effect of the sol aging time on SERS signal:SERS spectra of10?5M BCB on substrates coated with(a)5min aged sol and(b)2h aged sol.He–Ne laser power was8mW at632.8

nm.

Fig.5.The effect of elapsed time between coating and UV irradiation on SERS signal:SERS spectra of10?3M1-AP on a substrate irradiated(a)1/2h,(b) overnight*,(c)overnight and(d)4h after the coating process.He–Ne laser power was8mW at632.8nm.*:All the plates were dried at60?C after irradiation except(b)which was dried before irradiation.

664M.Volkan et al./Sensors and Actuators B106(2005)660–667

reprecipitation of the gel network[25].Zayat et al.[24]have recommended aging the sol–gel for1week during the prepa-ration of a photochromic sol–gel coating.According to our observations,however,for photochemical reduction imple-mented principally for the production of SERS-active silver nanoparticles on the surface,the aging time should be kept as short as possible.Fig.4displays the SERS spectra of10?5M BCB acquired using the substrates,which were coated imme-diately,as well as2h after the addition of AgNO3and TCAA to the sol.As can be seen from the?gure,better SERS sensi-tivity was achieved if the coating was performed without?rst aging the sol.This observation can be attributed to the more uniform distribution of precursor AgCl crystals and hence the subsequently formed silver nanoparticles on the surface. Since chloride ions are slowly released from TCAA,when the prepared sol was immediately applied to the glass support, a homogeneous mixture of AgNO3and TCAA could have been evenly distributed on the surface prior to any signi?cant AgCl crystal formation.On the other hand,for the case when the sol had been aged,AgCl crystals had been formed in

the Fig.6.Regeneration cycle of the photochromic SERS substrate:(a)SERS spectrum of10?3M1-AP on UV-reduced substrate;(b)SERS spectrum of substrate used in part(a)after exposure to HNO3vapor;(c)SERS spectrum of10?3M1-AP(new injection)on the substrate used in parts(a)and(b)after UV irradiation. He–Ne laser power was8mW at632.8nm.

M.Volkan et al./Sensors and Actuators B106(2005)660–667665

gel matrix prior to application to the glass support.As a re-sult,the distribution of the pre-formed AgCl crystals on the glass surface could have been in?uenced by the centrifugal force imposed by the spin coating process.Hence,coating was performed immediately after the addition of the AgCl precursors to the sol–gel.

A unique and advantageous feature of this new substrate is the fact that once the glass support is coated,the sit-ting time prior to SERS-activation via photoreduction is not very critical.For example,Fig.5(a,d and c)shows,respec-tively,the spectra of10?5M1-AP obtained with substrates which were irradiated after sitting1/2h,4h,and overnight, relative to the time of the coating step.As can be seen from the?gure,their intensities are all comparable.This re-sult implies that the substrate may have an extended shelf-life when stored in the non-reduced state.It is also impor-tant to note that the substrates were dried at60?C for1h prior to SERS measurement.The importance of the order of heating and UV-irradiation steps was investigated.The SERS activity was observed to be independent of the or-der.As depicted in Fig.5,the spectra of10?5M1-AP ob-tained with substrates dried overnight and heated at60?C before(b)and after(c)irradiation are similar.For all fur-ther studies the substrates were heated after the irradiation period.

SERS-active silver nanoparticles were generated from photo-induced reduction of Ag+ions from AgCl crystals. The sol–gel?lms exhibited deep darkening upon exposure to UV radiation.The minimum required irradiation time for an optimum SERS effect was determined to be10min.Be-yond this exposure time no increase in SERS activity was observed.It was also possible to record the SERS spectra of model compounds even if the AgCl sol–gel?lms were not exposed to UV radiation.This observation could be ex-plained by the fact that the excitation laser used for SERS measurements probably induced photoreduction of the silver ions.Nevertheless,SERS signals from substrates prepared in this fashion were not reproducible.Therefore,a10min UV irradiation time was used to photoreduce the SERS substrates throughout this work.

Shelf-life is generally a key issue in the development of a practical SERS substrate.For silver-based SERS substrates, degradation of SERS activity is typically observed with age due to the vulnerability of silver to air oxidation.This con-dition has contributed to the limited use of SERS in routine ?eld applications.The shelf-life of the substrates developed in this work can be superior to many previously developed SERS substrates when stored in the non-reduced form and in the dark.Actually the rate of deactivation of substrates in the?nal reduced form is not very fast.This fact could be at-tributed to the stabilization of the silver metal particles by the gel network of the inorganic polymer.However,it is still al-ways advisable to apply the UV-induced photoreduction and heating processes shortly before use.An additional practical feature of this new substrate is that even a degraded substrate (from aging in reduced form)can be reactivated by brief ex-posure to HNO3vapor,followed by re-irradiation with UV light.The exposure to the acid vapor is sustained until the dark-brown color of the substrate is replaced by the origi-nal white appearance,which corresponds to the non-reduced state.This photochromic behavior has been described[24]as the dissolution of silver metal particles by HNO3,and sub-sequent conversion of the silver back to AgCl crystals.Thus, bleaching of the dark color of the substrates was due to the oxidation of silver,while the darkened reduced state could subsequently be regained via exposure to UV radiation.The SERS sensitivity of a regenerated substrate was evaluated with1-AP.Fig.6(a)displays the SERS spectrum of10?3M 1-AP obtained with a1-day-old substrate.When the substrate was exposed to HNO3vapor,total loss of the SERS signal was observed,as demonstrated by Fig.6(b).This substrate was consequently irradiated with UV light and re-spiked with 1-AP.Fig.6(c)illustrates an intense SERS signal,which was obtained after regenerating the SERS substrate.It has been reported[24]that the darkening–bleaching cycle could be re-peated several times with sol–gel photochromic glasses

con-Fig.7.SERS spectra of10?3M1-AP on photochromic substrates at room temperature:(a)after5min exposure to air saturated with HNO3vapor;(b)after 20min exposure to air saturated with HNO3vapor;(c)after30min exposure to air saturated with HNO3vapor;(d)after60min exposure to air saturated with HNO3vapor.He–Ne laser power was8mW at632.8nm.

666M.Volkan et al./Sensors and Actuators B106(2005)660–667

taining AgCl crystals.In our study,this regeneration process was repeated,resulting in no observable change in the SERS activity for a single substrate when using a10?3M1-AP solution sample as the model.

As stated in the previous paragraph,the SERS spec-trum of1-AP has been observed to disappear after expos-ing the substrate to nitric acid vapor.We decided to exploit this feature for monitoring the vapor of strong acids.Three acids:HNO3,H2SO4and HCl were investigated.Reduced-form substrates were exposed overnight to the acid vapors at21?C.It was observed that the bleaching of the substrate and hence the disappearance of the SERS spectrum of1-AP was selective to HNO3vapor.This can be explained by the greater oxidation potential of HNO3relative to the other acids.In order to?nd the real response time for ni-tric acid vapor detection,substrates spiked with1-AP were exposed to HNO3vapor at21?C,in closed containers,for various time intervals(5–60min).Fig.7depicts the varia-tion in the1-AP SERS intensity with respect to the expo-sure time.As can be seen from Fig.7(c),the SERS signal started to diminish after a30min interval.After a1h ex-posure time,Fig.7(d),the1-AP signal disappeared com-pletely.Although the nitric acid vapor monitoring conditions have not been completely optimized,the results illustrated in Fig.7demonstrate that this new photochromic SERS sub-strate,when spiked with1-AP,has a potential to be used as a passive sampler or dosimeter for selective detection of HNO3 vapor.

4.Conclusion

A SERS-active medium of embedded Ag nanoparticles can be generated via photo-induced reduction of Ag+from a sol–gel containing AgCl crystals.An advantage of this method is the ease with which this SERS-active substrate can be produced.We have spin-coated this medium on a glass support to produce a sturdy,thin,translucent substrate which yields low background.Furthermore,this new substrate not only exhibits a relatively long shelf-life,but also is regen-erable through a simple chemical bleaching/photoreduction cycle.Experiments have shown that this substrate offers some chemical selectivity to HNO3vapor relative to HCl and H2SO4vapors.For substrates doped with1-AP,the SERS signal has been observed to disappear after a1h exposure to HNO3vapor at20?C.These studies have therefore demon-strated the potential for using the substrate described herein as a passive detector for HNO3vapor. Acknowledgements

This research was sponsored by the U.S.Department of Energy,Of?ce of Health and Environmental Research,under contract DE-AC05-00OR22725with UT-Batelle,L.L.C.;by the Laboratory Directed Research Program,Oak Ridge Na-tional Laboratory(ORNL);and by the Federal Bureau of Investigation(IAG no.20510-II18-Y2).This work was also supported in part by the appointment of D.L.Stokes to the ORNL Postdoctoral Research Associates Program,admin-istered jointly by ORNL and the Oak Ridge Institute for Science and Education.M.V olkan would like to acknowl-edge the Turkish Scienti?c and Technological Institute and the Middle East Technical University,Faculty of Arts and Sci-ences,Department of Chemistry,Ankara,Turkey,for support of the1997–1998sabbatical leave.

References

[1]M.J.Fleischmann,P.J.Hendra,A.J.McQuillan,Raman-spectra of

pyridine adsorbed at a silver electrode,Chem.Phys.Lett.(1974)26.

[2]R.L.Garrell,Surface enhanced Raman spectroscopy,Anal.Chem.

61(1989)A401–A411.

[3]A.Otto,I.Mrozek,H.Grabhorn,W.Akermann,Surface-enhanced

Raman scattering,J.Phys.Condens.Matter4(1992)1143–1212.

[4]T.V o-Dinh,Surface-enhanced Raman spectroscopy using metallic

nanostructures,Trends Anal.Chem.TRACs17(1998)557–582. [5]Y.S.Li,J.C.Cheng,L.B.Coons,A silver solution for sur-

face enhanced Raman scattering,Spectrochim.Acta A55(1999) 1197–1207.

[6]S.Zou,M.J.Weaver,Q.X.Li, B.Ren,Z.Q.Tian,New strate-

gies for surface enhanced Raman scattering at transition metal interfaces—thickness dependent characteristics of electrodeposited Pt-group?lms on gold and carbon,J.Phys.Chem.B103(1999) 4218–4222.

[7]Y.H.Cao,Y.S.Li,Constructing surface roughness of silver for sur-

face enhanced Raman scattering by self-assembled monolayers and selective etching process,Appl.Spectrosc.53(1999)540–546. [8]D.Gerrard,J.Birnie,Raman spectroscopy,Anal.Chem.64(1992)

R502–R513.

[9]T.V o-Dinh,M.Meier, A.Wokaun,Surface-enhanced Raman-

spectrometry with silver particles on stochastic-post-substrates,Anal.

Chim.Acta181(1986)139–148.

[10]D.L.Stokes,A.Pal,V.A.Narayanan,T.V o-Dinh,Evaluation of

a chemical vapor dosimeter using polymer-coated SERS substrates,

Anal.Chim.Acta399(1999)265–274.

[11]H.Z.Yu,J.Zhang,H.L.Zhang,Z.F.Liu,Surface enhanced Ra-

man scattering(SERS)from azobenzene self-assembled sandwiches, Langmuir(1999)15.

[12]Q.Cao,F.T.Li,Y.Lu,G.Xue,The adsorption of2-mercaptoethanol

on silver mirror and HCl etched iron,Spectrosc.Lett.31(1998) 167–175.

[13]N.J.Szabo,J.D.Winefordner,Evaluation of a solid-phase extraction

membrane as a surface enhanced Raman substrate,Appl.Spectrosc.

52(1998)500–512.

[14]W.H.Li,X.Y.Li,N.T.Yu,Surface enhanced hyper Raman spec-

troscopy(SEHRS)and surface enhanced Raman(SERS)studies of pyrazine and pyridine adsorbed on silver electrodes,Chem.Phys.

Lett.305(1999)303–310.

[15]T.V o-Dinh,M.Y.K.Hiromoto,G.M.Begun,R.L.Moody,Surface-

enhanced Raman spectrometry for trace organic-analysis,Anal.

Chem.56(1984)1667–1670.

[16]H.Gliemann,U.Nickel,S.Schneider,Application of photographic

paper as a substrate for surface enhanced Raman spectroscopy,J.

Raman Spectrosc.29(1998)1041–1046.

[17]S.W.Han,H.S.Han,K.Kim,Infrared and Raman spectra of4-

cyanobenzoic acid on powdered silver,Vibrat.Spectrosc.(1999)21.

[18]D.X.Wang,S.L.Chong,A.Malik,Sol–gel column technology for

single step deactivation coating and stationary phase immobilization

M.Volkan et al./Sensors and Actuators B106(2005)660–667667

in high resolution capillary gas chromatography,Anal.Chem.69 (1997)6–4576.

[19]L.Yang,S.S.Saavedra,Chemical sensing using sol–gel derived

planar wave guides and indicator phases,Anal.Chem.67(1995) 1307–1314.

[20]F.Akbarian,B.S.Dunn,J.I.Zink,Surface enhanced Raman spec-

troscopy using photodeposited gold particles in porous sol–gel sili-cates,J.Phys.Chem.99(1995)3892–3894.

[21]M.V olkan,D.L.Stokes,T.V o-Dinh,A new surface enhanced Raman

scattering substrate based on silver nanoparticles in sol–gel,J.Raman Spectrosc.30(1999)1057–1065.

[22]W.H.Armistead,S.D.Stookey,Photochromic silicate glasses sensi-

tized by silver halides,Science144(1964)150–154.

[23]M.Zayat,D.Einot,R.Reisfeld,In situ formation of nanocrystallites

prepared by the sol–gel and silver nanoparticles in silica glass?lms, J.Sol–Gel Sci.Technol.10(1997)67–74.

[24]M.Zayat, D.Einot,R.Reisfeld,Reversible photochromism of

sol–gel SiO2:AgCl?lms,J.Sol–Gel Sci.Technol.10(1997) 203–211.

[25]L.L.Hench,J.K.West,The sol–gel process,Chem.Rev.90(1990)

33–72.

Biographies

M¨urvet Volkan received her Ph.D.in1985in analytical chemistry from Middle East Technical University,Ankara.She is presently professor of analytical chemistry at the same University and is involved in the devel-opment of sensors,?ow injection analyses methods and in the preparation and characterization of magnetic nano particles.

Dr.David L.Stokes received his Ph.D.in Chemistry from the University of Tennessee in1999,and his B.S.in Physics(broad science)from the University of the South,Sewanee,in1988.From1988–2003,Dr.Stokes performed analytical chemistry research at Oak Ridge National Labo-ratory.His expertise spans many areas of molecular spectroscopy with applications in remote sensors for environmental and biomedical studies. He has authored or co-authored over40publications in peer-reviewed sci-enti?c journals,and has been a co-recipient of three R&D-100Awards, conferred by R&D Magazine for the development of One of The Most Technologically Signi?cant New Products of1992,1996,and2003.He is currently employed by EOIR Technologies,Woodbridge,V A,where he works as a sensors research scientist.

Dr.Tuan Vo-Dinh is currently a Corporate Fellow,Group Leader of the Advanced Biomedical Science and Technology Group,and Director of the Center for Advanced Biomedical Photonics at the Oak Ridge Na-tional Laboratory(ORNL),Oak Ridge,Tennessee,USA.He received his Ph.D.in Biophysical Chemistry in1975from the Swiss Federal Insti-tute of Technology(known as ETH)in Zurich(Switzerland).His re-search interests focus on the development of advanced technologies for human health protection and environmental sensing.His research activi-ties involve medical diagnostics,molecular imaging,laser spectroscopy, biophotonics,biosensors,nanosensors,and biochips.Dr.V o-Dinh has au-thored over300publications in peer-reviewed scienti?c journals.He is the author and editor of6books,and holds over28U.S.patents,6 of which have been licensed to private companies for commercial de-velopment.Dr.V o-Dinh has received numerous awards including seven R&D-100Awards for Most Technologically Signi?cant Advance in Re-search and Development for his development of various technologies:the Gold Medal Award,Society for Applied Spectroscopy;the Languedoc-Roussillon Award(France);the Scientist-of the-Year Award,Oak Ridge National Laboratory;the Thomas Jefferson Award,Martin Marietta Cor-poration;the Distinguished Inventors Award,Battelle Memorial Institute; and the Exceptional Services Award for distinguished contribution to a Healthy Citizenry from U.S.Department of Energy.

各大仿真软件介绍

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4、加上一个异步清零端,点Next,再点Next,最后点Finish. Add/Remove Files in Project…,

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