Rhodium-Prussian Blue modified carbon paste electrode (Rh-PBMCPE) for amperometric detection of hydrogen peroxide

Abstract

Filmes de azul da Prússia foram superficialmente depositados em eletrodos de pasta de carbono a partir de soluções contendo 2,0 x 10 -3 mol L -1 de K 3 [Fe(CN) 6 ], 3,0 x 10 -3 mol L -1 FeCl 3 e 1,0 x 10 -2 mol L -1 HCl, usando dois potenciais controlados. Para aumentar a estabilidade do eletrodo modificado, efetuaram-se 50 ciclos em solução contendo 1,0 x 10 -3 mol L -1 de RhCl 3 , 0,50 mol L -1 de KCl e 1,0 x 10 -2 mol L -1 de HCl no intervalo de -0,40 a + 0,60 V a 60 mVs -1 . Estes eletrodos, denominados de Rh-PBMCPE, apresentaram boa estabilidade durante a determinação amperométrica de H 2 O 2 a 0,040 V sem a interferência dos ácidos ascórbico e úrico. A corrente de redução variou linearmente com a concentração de H 2 O 2 no intervalo de 5,0 x 10 -5 a 8,6 x 10 -4 mol L -1 . O limite de detecção foi de 2,8 x 10 -5 mol L -1 com sensibilidade variando de 1,32 a 0,96 A mol -1 L cm -2 ao longo de cinco dias (180 determinações).Prussian Blue was deposited at carbon paste electrode surface from a solution containing 2.0 x 10 -3 mol L -1 K 3 [Fe(CN) 6 ], 3.0 x 10 -3 mol L -1 FeCl 3 and 1.0 x 10 -2 mol L -1 HCl using two controlled potentials. To improve the stability of the modified electrode it was 50 times cycled in a solution containing 1.0 x 10 -3 mol L -1 RhCl 3 , 0.50 mol L -1 KCl and 0.010 mol L -1 HCl in the potential range from -0.40 V to 0.60 V at 60 mV s -1 . The Rh -Prussian Blue carbon paste modified electrode (Rh-PBMCPE) showed good stability during amperometric catalytic determination of H 2 O 2 at 0.040 V, without ascorbic and uric acids interferences. The current changed linearly with H 2 O 2 concentrations in the range of 5.0 x 10 -5 -8.6 x 10 -4 mol L -1. The estimated detection limit was 2.8 x 10 -5 mol L -1 with sensibility changing from 1.32 to 0.96 A mol -1 L cm -2 along five days (180 determinations).Keywords: prussian blue, rhodium, carbon paste electrode, hydrogen peroxide, amperometry IntroductionPrussian Blue modified electrodes (PBME) have been prepared by electrochemical techniques on electrodes such as glassy carbon, 1-18 platinum, 1,3,19,[20][21][22][23] tin oxide, 1,3,[24][25][26] gold, 3 graphite, 27-28 titanium-silver-gold arrays, 29 basal pyrolytic graphite, 30 screen printed carbon ink interdigital arrays, 20 conducting polymer coated microelectrode arrays, 31 carbon fiber, 32 carbon paste, 33 etc.They were used to design new glucose, [8][9][10]17,21,23,28,30,32 alanine, 30 alcohol 30 and glutamate 13,14 biosensors based on the electrochemical detection of hydrogen peroxide, which is formed in the course of the substrate enzyme-catalyzed oxidation. In these cases Nafion, 8,10,14,17,30 poly (ophenylenediamine), 21 polypyrrole/poly (o-phenylenediamine) 23 and poly (o-diaminebenzene) 18 polymers have been used to immobilize the enzyme and eliminate interferences from ascorbic and uric acids. Chemical preparations were also described and involve the immersion of the working electrode in aqueous modifier solution, 5,6,19 the mixture of Prussian Blue (chemically synthesized) with gra...

Rhodium stabilized Prussian Blue-modified graphite electrodes for H2O2 amperometric detection

“…1), simultaneously with a slight decrease in reversibility for the heterogeneous charge transfer process (resulting from variations of the electrochemical parameters). As was found in the case of the stabilizing effect of Ru 3+ on Co(II)-, Ni(II)-, In(III))-hexacyanoferrates, and Fe(II/III)-hexacyanorutenate [25-27, 30, 31], the stabilizing effect of Rh 3+ [28] should be due to its ability to establish an extensive cross linking between hydrate microparticles through dinuclear oxo and cyanide bridges [25,30]. Moreover, it was shown that the presence of K + ion during the potential cycling of the G/PB electrodes induces a stabilization effect, attributable to a gradual transformation of the ''insoluble'' PB into its ''soluble'' form [32][33][34].…”

“…Based on recently published results, which describe the beneficial effect of Ru 3+ [25][26][27] and Rh 3+ [28] on the stability of PB and its analogues (Ni(II)-, In(III)-, and Co(II)-hexacyanoferrates), the present work aims, firstly, to investigate the influence of Rh 3+ on the electrochemical behavior of PB. Secondly, PB-modified graphite electrodes (G/PB), obtained using the Ricci method [23] All solutions were prepared with purified water from a Milli-Q system (Millipore, Milford, USA) and the optimal pH was adjusted using a MV-870 Digital pH-meter (Pracitronic, Germany).…”

A new amperometric glucose biosensor based on screen printed carbon electrodes with rhenium(IV) - oxide as a mediator

“…In many cases transition metal compounds are used which may change easily their oxidation states such as hexacyanoferrates [8][9][10][11][12][13][14][15][16][17], platinum metals or their oxides [18], and manganese dioxide [6][7][8][9][19][20][21].…”

Electrocatalytic Reduction of Hydrogen Peroxide on Palladium-Gold Codeposits on Glassy Carbon: Applications to the Design of Interference-Free Glucose Biosensor

“…Various types of carbonaceous materials have been investigated most often as modified electrodes for determining H 2 O 2 : graphite [6,14], glassy carbon [7,8,10,[15][16][17][18][19], carbon-paste electrodes [20,21], carbon nanotubes [22][23][24], and so forth. With these electrodes, the selectivity of the electrochemical response to hydrogen peroxide is improved by using different catalytically active modification components: transition metals and their oxides [15,21], platinum metals, dispersed on their own or mixed with other platinum metals [7,25], and with nanostructured composite films [8,26].…”