Estudo matemático de estabilidade do desempenho do sistema [Fe(CN)6]3–/[Fe(CN)6]4– como mediador na eletrorredução de nitrito, com fins eletroanalíticos

O desempenho do sensor de nitrito, baseado no elétrodo, modificado pelo sistema de hexacianoferratos (II) e (III) como mediador, foi descrito matematicamente, sendo o modelo matemático correspondente analisado mediante a teoria de estabilidade lineal e análise de bifurcações. O modelo foi comparado com os análogos e com os sistemas experimentais.The work of nitrite sensor, based on the electrode, modified by the system of hexacianoferrates (II) and (III) as mediator, was mathematically described, and the corresponding mathematical model was analyzed by means of linear stability theory and bifurcation analysis. The model was compared with its analogues and experimental systems

A descrição matemática do desempenho de sensores e biossensores eletroquímicos de ph, baseados em polímeros condutores, nos processos de medição do ph dos líquidos de cavidade bucal no modo de voltagem constante

O desempenho de sensores e biossensores de pH, baseados nos polímeros condutores, usados no modo de voltagem constante para medir o pH da cavidade bucal, foi descrito matematicamente. Por meio da análise do respetivo modelo, foram inferidas as condições da melhor precisão do indicador, da multiplicidade de estado estacionário e do comportamento oscilatório em parâmetro eletroquímico

SUCRALOSE CoO(OH)-ASSISTED ELECTROCHEMICAL DETECTION IN ALKALINE MEDIA. THE THEORETICAL ANALYSIS OF AN INTERESTING POSSIBILITY

The sucralose electrochemical determination, assisted by cobalt (III) oxyhydroxide, has been theoretically evaluated. The mathematical model, describing the electroanalytical process, has been developed. The analysis of the model by linear stability theory and bifurcation analysis has shown that CoO(OH) may be applied as an efficient electrode modifier in the sucralose determination in neutral and lightly alkaline media. The electrochemical response has to be clear and easy to interpret. The oscillatory and monotonic instabilities may occur due to double electric layer influences of the electrochemical process

THE THEORETICAL DESCRIPTION FOR ECOPIPAM ELECTROCHEMICAL DETERMINATION ON A COBALT(III) OXYHYDROXIDE-BASED MATERIAL

The theoretical description for ecopipam electrochemical determination, assisted by cobalt(III) oxyhydroxide has been given. The correspondent mathematical model has been developed and analyzed by means of linear stability theory and bifurcation analysis. It has been shown that, despite of the electrochemical instabilities, more probable to occur than for the similar systems, the cobalt (III) oxyhydroxide is an efficient electrode modifier for ecopipam determination. The electroanalytical process is diffusion-controlled

A avaliação mecanística teórica da utilização de oxihidróxido de cobalto (III) em sensores eletroquímicos de tramadol

A possibilidade da detecção eletroquímica de tramadol in vivo e in vitro por meio dosensor, baseado em oxihidróxido de cobalto trivalente e no seu compósito com polímeroscondutores, foi avaliada do ponto de vista mecanístico. O modelo matemático,correspondente ao mecanismo de oxidação sugerido, foi desenvolvido e analisado,mediante a teoria de estabilidade linear e da análise de bifurcações. Foi detectadoque CoO(OH) pode aplicar-se na detecção eletroquímica de tramadol nos valoresde pH neutros e levemente alcalinos, correspondentes à oxidação mais eficiente docomposto. A possibilidade da aparição de instabilidades oscilatória e monotônicatambém foi verificada.The possibility of tramadol in vivo and in vitro electrochemical determination bymeans of the sensor, based on cobalt (III) oxyhydroxide and its composite withconducting polymers was evaluated from the mechanistic point of view. The mathematicalmodel, correspondent to the suggested mechanism, was developed andanalyzed by means of linear stability theory and bifurcation analysis. It was shownthat CoO(OH) may be applied to the tramadol electrochemical determination inneutral and lightly alkaline pH values, correspondent to the more efficient oxidationof the compound. The possibility of oscillatory and monotonic instabilities has alsobeen modified

The Theoretical Description for the Perylaldehyde Aldoxyme Anodic Electrochemical Determination, Assisted by the Novel Squaraine Dye Composite with Copper(ii) Sulfide Nanoparticles

In this work the perillaldehyde aldoxime electrochemical determination on an anode, modified by squaraine dye composite with copper sulfide nanoparticles is analyzed. The electroanalytical process involves the formation of trivalent copper species, capable to oxidize the analyte by two parallel mechanisms. The correspondent mathematical model, correspondent to both of them, has been developed and analyzed by means of linear stability theory and bifurcation analysis. The model analysis clearly shows that the composite of a squaraine dye in organic phase and bivalent copper sulfide in the inorganic phase may be an efficient electrode modifier for perillaldehyde aldoxime electrochemical determination on an anode. The electroanalytical process will be mostly kinetically-controlled with the possibility of the transfer to diffusion-controlled mode. On the other hand, both oscillatory and monotonic instabilities may be realized in the electroanalytical process, and their probability will depend on the direction of the electroanalytical scenario in the concrete conditions, due to the possibility of the formation of ionic compounds in the pre-surface layer. DOI: http://dx.doi.org/10.17807/orbital.v13i5.150