Effect of the Concentration of Supporting Electrolyte on Spectroelectrochemical Detection of [Ru(bpy)₃]²⁺

Abstract

The effect of different concentrations of supporting electrolytes, either KNO 3 , NaNO 3 or Ca(NO 3 ) 2 , on the response of a spectroelectrochemical sensor was examined using [Ru(bpy) 3 ] 2 + as the analyte. The sensor consisted of an indium tin oxide (ITO) optically transparent electrode (OTE) coated with a thin film of either Nafion or SSEBS (sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block polystyrene) and used attenuated total reflection absorbance for optical detection and cyclic voltammetry for electrochemical detection. The practical implication of these results is the need to take into account the effect of ionic strength of the sample when using a spectroelectrochemical sensor of this type for quantitative analysis.

Simplified Nitrate-Reductase-Based Nitrate Detection by a Hybrid Thin-Layer Controlled Potential Coulometry/Spectroscopy Technique

“…The lower concentration of supporting electrolyte causes high solution resistance and IR drop, which lowers the current response and makes the peaks less distinguishable. 31 In 0.5 M Na 2 SO 4 , the peaks at −761 mV (E pc ) and −624 mV (E pa ) corresponded to the reduction and oxidation of MV 2+ and MV +• , respectively. The calculated redox potential of MV 2+ / MV +• from the average of the peak potentials is −692.5 mV, which agrees with the redox potential obtained by spectroelectrochemistry in a thin-layer cell (Figure S1).…”

“…As shown in Figure B, in 0.1 M Na 2 SO 4 , the voltammetric peaks are less well-defined compared with higher concentrations. The lower concentration of supporting electrolyte causes high solution resistance and IR drop, which lowers the current response and makes the peaks less distinguishable . In 0.5 M Na 2 SO 4 , the peaks at −761 mV ( E pc ) and −624 mV ( E pa ) corresponded to the reduction and oxidation of MV 2+ and MV +• , respectively.…”

Modeling the Influence of Low Concentrations of Water on the Thermodynamics, Electron Transfer Kinetics, and Diffusivity of the [Ru(CN)6]4–/3– Process in Propylene Carbonate

“…The cell, electrodes, and other conditions were the same as for DC voltammetry. FTAC voltammetric data obtained from either experiment or simulation in the time domain were converted to the frequency domain to generate the power spectrum. , Frequencies corresponding to the AC harmonics and DC component were selected from the power spectrum and then subjected to band filtering and inverse Fourier transformation to obtain resolved DC and AC components.…”

Study on Combined Optical and Electrochemical Analysis Using Indium‐tin‐oxide‐coated Optical Fiber Sensor

“…The concentration of these electrolytes is usually between 0.01 M and 1.0 M and is higher than the one of the investigated analyte . The main role of the electrolyte is to lower the solution resistance between electrodes and to eliminate migration of the analyte to the working electrode .…”