, ( :0646 : A. . Wang [5 ] Penven [8 ] [ Pd (N H 3 ) 2 Cl 2 + N H 4 Cl ] p H. p H Penven. Vol. 6 No. 2 May EL ECTROCHEMISTR Y

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1 EL ECTROCHEMISTR Y Vol 6 No 2 May 2000 : (2000) , (, ) 3 : Pd(NH 3 ) 2 Cl 2, ( GOD) UV/ V Pd 2 +, p H Pd, GOD : -,,, :0646 : A, [1 ( ) ] [2 ] [3 ] [4 ] [5 7 ],,,, Wang [5 ] Penven [8 ] [ Pd (N H 3 ) 2 Cl 2 + N H 4 Cl ] ( GOD),, p H 4, Penven, p H7 10,,,, Pd, p H,, : : ( )

2 Pd( HN 3 ) 2 Cl 2 Metalor, ( ) GOD ( E C ,23800 u/ g) - D ( + ) Sigma, A, 1 5 g/ L Pd ( HN 3 ) 2 Cl mol/ L (p H 3 9), p H A GOD B, A 5 g/ L GOD ( ) 3066X- Y ( ) 173 ( EG &G PAR ),, ( GC), 6 # 5 m Al 2 O 3, MC - ( ) [9,10 ], 1 a b Pd (N H 3 ) 2 Cl 2, nm, ( c), 315 nm : 0 2 mol/ L Pd (N H 3 ) 2 Cl g/ L 1 Pd(NH 3 ) 2 Cl 2 UV/ V, g/ L 315 nm, Fig 1 The UV/ V absorption spectra for glycine, and Pd(NH 3 ) 2 Cl 2 aqueous solutions 1 2, curves : (a) 0 2 mol/ L glycine, (b) 1 5, g/ L 315 g/ L Pd ( NH 3 ) 2 Cl 2, (c) mixure of two nm, solutions

3 2 : UV/ V A p H Table 1 Variation of UV/ V adsorption spectra with p H values of bath A(1 5 g/ L Pd(NH 3 ) 2 Cl mol/ L glycine p H of solutions peaks in spectra/ nm ,380, , , , ,338 absorbance 1 9,2 4, , , , ,1 7 A p H,, 1 p H, p H 2 3, p H 10 2, Penven [8 ] Pd (N H 3 ) 2 Cl nm, 297 nm : Pd (N H 3 ) 2 Cl 2 + 2H + + 2Cl 2 = [ PdCl 4 ] N H 4 + Pd (N H 3 ) 2 Cl 2 + 2N H 3 = [ Pd (N H 3 ) 4 ] Cl -, : Pd (N H 3 ) 2 Cl 2 + R = [ Pd(N H 3 ) 2 RCl ] + + Cl - [ Pd (N H 3 ) 2 RCl ] + + R = [ Pd(N H 3 ) 2 R 2 ] Cl - R p H nm A [ PdCl 4 ] 22, p H nm [ Pd (N H 3 ) 2 RCl ] + N H 3 Cl -,,p H 4 10, p H, p H, N H 3, ( 5 97 [9 ] ), A, Pd (N H 3 ) 2 Cl 2 + N H 4 Cl [8 ], 0 V, p H 8 p H 10, V [11, ] p H, p H Penven [8 ], 2, p H p H 4 10,,p H 2, V [8, ] p H 2,,

4 A Fig 2 Voltammograms of a glassy carbon electrode in plating solution A (1 5 g/ L Pd(NH 3 ) 2 Cl mol/ L glycine) with various p H v = 50 mv/ s, curves :p H (a) 2 0, (b) 4 0, (c) 6 0, (d) 8 0, (e) GOD, p H GOD ( 4 2 [12 ] ) A p H 3 9, 3 A ( ) B ( ), B Pd V, A, Pd GOD Ag + [12 ], Pd 2 + Penven [8 ], 150 mv, 3 A ( ) B ( ), V (vs SCE) SEM, Fig 3 Voltammograms in bath A (solid, line) and bath B ( dotted line),, 50 mv/ s, Solution Component : A : same as Fig 2 ; B : A + 5 g/ L GOD, 2 b, V

5 2 : 161 (a) (b) 4 A (a) B (b) SEM Fig 4 SEM pictures of the eldctrode surface after deposited in bath A(a) and bath B(b) magnification 7000, 4 A B Pd/ GC Pd- GOD/ GC SEM ( V, 5 min),,pd, B,, Pd- GOD/ GC V H 2 O 2, Electrochemical Codeposition of Palladium and Glucose Oixdase in t he Presence of Glycine as Complexing Agent ZHU Kan, WU Hui- huang 3 ( Dept of Chem, S tate Key L ab f or Phys Chem of the Solid S urf aces, Xiamen U niv, Xiamen , China) Abstract : Glycine and Pd (N H 3 ) 2 Cl 2 consist of a solution for the electrochemical codeposi2

6 tion of Pd and glucose oxidase ( GOD) to prepare a metallized enzyme elect rode The experiment s by UV/ V spectroscopy show that the complexing of Pd ion with glycine can occur, which makes t he plating bat h has relatively stable chemical composition in a certain p H range The voltammet2 ric experiment s indicate t hat t he presense of glycine decreases t he potential of Pd deposition,facil2 itating to prevent t he formation of palladium hydride The appropriate conditions for t he elect ro2 chemical codeposition of Pd and GOD are discussed Key words : Palladium-glycine complexes, Glucose oxidase, Electrochemical codeposition, Metallized enzyme elect rodes Reference s : [ 1 ] Belanger D, Brassard E, Fortier G, Enhancement of response by incorporation of platinum microparticles into a polypyrrole-glucose oxidase electrde [J ] Anal Chim Acta, 1990, 228 : [2 ] Heider G H, Sasso S V, Huang K, Yacynych A M, Weck H J, Electrochemical platinization of reticulated vitreous carbon electrodes to increase biosensor response [J ] Anal chem, 1990, 62 : [3 ] Kim C S, Oh S M, Enzyme sensors prepared by electrodeposition on platinized platinum electrodes [J ] Elec2 trochim Acta, 1996, 41 : [ 4 ] Wang, J, Naser N, Angnes L, Wu H, Chen L, Metal- dispersed carbon paste electrodes [J ] Anal Chem, 1992, 64 : [ 5 ] Sakslund H, Wang J, A critical evaluation of a glucose biosensor by codeposition of palladium and glucose oxi2 dase on glassy carbon [J ]J Electroanal Chem, 1994, 374 : [6 ] Chi Q, Dong S, Flow-injection analysis of glucose at an amperimetric glucose sensor based on electrochemical codeposition of palladium and glucose oxidase on a glassy carbon electrode [J ] Anal Chim Acta, 1993, 278 : [7 ] Sakslund H, Wang J, Lu F, Hammerich O, Development and evaluation of glucose microsensors based on electrochemical codeposition of ruthenium and glucose oxidase onto carbon fiber micro- electrodes [J ] J Elec2 troanal Chem, 1995, 397 : [8 ] Penven R Le, Levason W, Pletcher, D, Studies of the electtrodeposition of palladium from baths based on [ Pd(NH 3 ) 2 X 2 ] salts [J ] J Appl Electrochem, 1990, 20 : [ 9 ] J I Liang- nian, Mo Ting- huan Bioinorganic Chemistry, An Introductin[ M ] Guangzhou : Zhongshan Univer2 sity Press,1992 [10 ] WU Bao- Zhang L IN Li-fen,Photometric studies of Cu( )- amino acid Complexes[J ] Chemical Research and Applications(in Chinese),1998,8 : [11 ] WU Hui- huang,xu Shu- kai, ZHOU Shao- min Electronucleation mechanism of zinc on glassy carbon[j ] Acta Physico- Chimica Sinica(in Chinese), 1985,1 : [12 ] WU Hui- huang, ZHEN Zhi- min, ZHOU Shao- min Electrochemical activity of glucose oxidase- modified electroes [J ] Acta Chimica Sinica(in Chinese),1991,99 :