The electroactive integrated optical waveguide: Ultrasensitive spectroelectrochemistry of submonolayer adsorbates

被引:75
作者
Dunphy, DR
Mendes, SB
Saavedra, SS
Armstrong, NR
机构
[1] UNIV ARIZONA,DEPT CHEM,TUCSON,AZ 85721
[2] UNIV ARIZONA,CTR OPT SCI,TUCSON,AZ 85721
关键词
D O I
10.1021/ac961272g
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
Highly sensitive spectroelectrochemistry of adsorbed films on ITO is demonstrated with the electroactive integrated optical waveguide(EA-IOW), The EA-IOW, a single-mode planar waveguide coated with an ITO layer, is similar to 10(4)-fold more sensitive to changes in absorbance occurring during electrochemical events versus a single-pass transmission spectroelectrochemical experiment, as demonstrated by reduction of surface-adsorbed methylene blue. Furthermore, the EA-IOW is selective to near-surface events, as it is relatively insensitive to absorbance by solutions of dissolved chromophores at <1 mM. The EA-IOW is also used to monitor the formation of Prussian Blue during the reduction of ferricyanide, an event that is not easily followed using current-detected cyclic voltammetry, due to interfering faradaic and non-faradaic electrochemical events. The optical background of the EA-IOW is potential-dependent and is explained by ion diffusion into the ITO and by voltage-dependent changes in optical constants for the material, Finally, the high sensitivity of the EA-IOW (relative to other evanescent-field-based spectroelectrochemical techniques) is discussed in terms of its design.
引用
收藏
页码:3086 / 3094
页数:9
相关论文
共 37 条
[1]  
ADAMSON AW, 1976, PHYSICAL CHEM SURFAC, P420
[2]   DIFFERENTIAL-CAPACITANCE STUDIES OF SILANE-MODIFIED SNO2 ELECTRODES AT LOW MODULATION FREQUENCIES [J].
ARMSTRONG, NR ;
SHEPARD, VR .
JOURNAL OF PHYSICAL CHEMISTRY, 1981, 85 (20) :2965-2970
[3]  
BARD AJ, 1980, ELECTROCHEMICAL METH, P586
[4]   SURFACE POLARITONS - PROPAGATING ELECTROMAGNETIC MODES AT INTERFACES [J].
BURSTEIN, E ;
CHEN, WP ;
CHEN, YJ ;
HARTSTEIN, A .
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY, 1974, 11 (06) :1004-1019
[5]   CRYSTAL-STRUCTURE OF PRUSSIAN BLUE - FE4[FE(CN)6]3.XH2O [J].
BUSER, HJ ;
SCHWARZENBACH, D ;
PETTER, W ;
LUDI, A .
INORGANIC CHEMISTRY, 1977, 16 (11) :2704-2710
[6]   TRANSPARENT CONDUCTORS - A STATUS REVIEW [J].
CHOPRA, KL ;
MAJOR, S ;
PANDYA, DK .
THIN SOLID FILMS, 1983, 102 (01) :1-46
[7]   PLANAR WAVE-GUIDE IMMUNOSENSOR WITH FLUORESCENT LIPOSOME AMPLIFICATION [J].
CHOQUETTE, SJ ;
LOCASCIOBROWN, L ;
DURST, RA .
ANALYTICAL CHEMISTRY, 1992, 64 (01) :55-60
[8]   DIFFUSION BARRIER OF SOL-GEL DERIVED SILICA FOR SPRAYED TIN OXIDE FILM ON SODA-LIME GLASS [J].
DAVIES, BM ;
PANNELL, KH ;
ALBRIGHT, SP .
JOURNAL OF MATERIALS RESEARCH, 1994, 9 (01) :226-228
[9]   THIN-FILM PLANAR WAVE-GUIDE SENSOR FOR LIQUID-PHASE ABSORBENCY MEASUREMENTS [J].
DEGRANDPRE, MD ;
BURGESS, LW ;
WHITE, PL ;
GOLDMAN, DS .
ANALYTICAL CHEMISTRY, 1990, 62 (18) :2012-2017
[10]  
DUNPHY DR, UNPUB