Influence of the adsorption phenomena on the NPP and RPP limiting currents for labile metal-macromolecule systems

Voltammetric lability of multiligand complexes: the case of ML2

“…. ; z N À1 ; z N Þ adapted to the problem [10][11][12][13]. Indeed, if h n ¼ z n À z nÀ1 , the values of these steps h n increase, for example, from 10 À4 to 10 À1 , in units of 1= ffiffiffiffiffiffiffi D M p increasing the number of spatial points so that the distance between them is reduced close to the electrode where the gradient of the unknown functions are expected to be greater.…”

“…Applying the FEM [4,[10][11][12][13][14] to the spatial part and the Inverse-Euler scheme to the temporal part [15], we obtain the following system of equations: where A and B are the usual symmetric matrices that appear in the application of the FEM method [11]:…”

Dynamics of Biouptake Processes: The Role of Transport, Adsorption and Internalisation

“…A reported analytical solution for the nonlinear problem of diffusion coupled with complexation kinetics was erroneous [12]. Thus, techniques such as the finite element method [53][54][55] or appropriate change of variables (applicable in some cases of planar diffusion) [56] should be used to find the numerical solution. One particular case of the nonlinear problem where an analytical solution can be given is the steady-state for fully labile complexes (see Section 3.3).…”

Voltammetry of heterogeneous labile metal–macromolecular systems for any ligand to metal ratio: part IV. Binding curve from the polarographic waves

“…From this analysis, the inverse problem, i.e., the determination of the binding curve from a titration experiment when the complex behaves as fully labile has been considered. Among the advantages of using the limiting currents we highlight the independence of the current from the concrete potential applied and the reduced influence of induced adsorption on the electrode surface if limiting currents are measured with suitable techniques such as reverse pulse polarography (RPP) [5,6] or stripping chronopotentiometry at scanned deposition potential (SSCP) [7]. Among the drawbacks, some systems behaving as labile at the foot of the polarographic wave can exhibit some loss of lability under diffusion limited conditions [8], which is a phenomenon not considered in the procedure.…”