Application Finder

Electrochemistry, spectroscopy, and spectroelectrochemistry (SEC) are widely used techniques in many fields. However, the data curves obtained from these analyses are quite varied, and not all electrochemical peaks and spectroscopic bands can be measured with the same procedures. This Application Note examines four tools included in the DropView 8400 and DropView SPELEC softwares to facilitate the measurement and analysis of the collected curves and data. The following measurement options are explained in detail: automeasurement, set on curve measurement, set free measurement, and set step measurement.

This Application Note highlights the use of Metrohm Hyphenated EC-Raman Solutions to monitor the reversible oxidation of ferrocyanide at a gold electrode. Variations of the band intensities with the potential can be used to track relative changes in the concentration profile of ferrocyanide and ferricyanide at the surface of the electrode during cyclic voltammetry (CV).

This Application Note presents a walkthrough of an experiment on 4-nitrothiophenol using hyphenated EC-Raman, a combination of Raman spectroscopy and electrochemistry.

In this Application Note, the Metrohm DropSens SPELEC instrument is used with the FLUORESCENCE KIT for time-resolved monitoring of electrochemical reactions in a semi-infinite diffusion regime by performing fluorescence spectroelectrochemistry of the [Ru(bpy)3]2+/3+ redox couple.

Alamar Blue is monitored with fluorescence spectroelectrochemistry during its irreversible reduction to resorufin and further reversible reduction to dihydroresorufin.

Substrates for surface-enhanced Raman spectroscopy (SERS) are typically fabricated with complex (micro/nano)structures of noble metals, enabling trace level detection of analytes. Due to the high costs and reactivity of these SERS substrates, they often have a limited shelf life. Development of new substrate materials which minimize these issues yet maintain the same performance standards is a constant concern.Screen-printed electrodes can be easily fabricated using different metallic materials with the well-established screen-printing method, leading to mass production of versatile, cost-effective, and disposable devices. In this Application Note, the feasibility of using readily-available screen-printed metal electrodes as suitable substrates for the fast and sensitive detection of different chemical species by in situ electrochemical SERS (EC-SERS) is shown.

Spectroelectrochemistry is a multi-response technique that provides both electrochemical and spectroscopic information about a chemical system in a single experiment, i.e., it offers information from two different points of view. Spectroelectrochemistry focused on the UV/VIS region is one of the most important combinations because this allows us to obtain not only valuable qualitative information, but also outstanding quantitative results. In this application note, the degradation kinetics for 4-nitrophenol, a known pollutant, were determined using SPELEC.

Spectroelectrochemistry is a multi-response technique that provides electrochemical and spectroscopic information about a chemical system in a single experiment, i.e., it offers information from two different points of view. Raman spectroelectrochemistry could be considered as one of the best techniques for both the characterization and behavioral understanding of carbon nanotube films, as it has traditionally been used to obtain information about their oxidation-reduction processes as well as the vibrational structure. This application note describes how the SPELEC RAMAN is used to characterize single-walled carbon nanotubes by studying their electrochemical doping in aqueous solution as well as to evaluate their defect density.

Many electrochemical methods have been developed but are traditionally limited to aqueous media. Raman spectroelectrochemistry in organic solutions is an interesting alternative, but developing new EC-SERS procedures is still required. This Application Note demonstrates that the electrochemical activation of gold and silver electrodes enables the detection of dyes and pesticides in organic media.

Fentanyl, a powerful synthetic opioid, is illegally distributed worldwide. Overdosing can be fatal, causing symptoms like stupor, pupil changes, cyanosis, and respiratory failure. Just 2 mg of fentanyl can be lethal, depending on factors like body size and past usage. Given its severe impact, identifying and detecting fentanyl is crucial, as it has become a major public health crisis. Combining electrochemical surface-enhanced Raman spectroscopy (EC-SERS) with screen-printed electrodes (SPEs) offers a fast, effective, and precise method for detecting fentanyl.

Low sensitivity has limited the use of Raman spectroscopy as a detection method. However, the surface-enhanced Raman scattering (SERS) effect has improved its effectivity for analytical use. Aldehyde dehydrogenase (ALDH) and cytochrome c are analyzed by Raman spectroelectrochemistry as a proof of concept in this Application Note.

This Application Note compares SPELEC RAMAN and a standard Raman instrument by analyzing their performance in measuring single-walled carbon nanotubes (SWCNT).

Electrochemical Raman (EC-Raman) spectroscopy enhances comprehension of energy storage devices by tracking physicochemical changes. This note details EC-Raman findings during nickel-metal hydride (NiMH) battery charge and discharge simulations.

Spectroelectrochemical experiments not only provide outstanding qualitative information about samples, but also offer other quantitative data that can be considered when performing analyses. A single set of experiments allows analysts to obtain two calibration curves: one with the electrochemical data and another with the spectroscopic information. The concentration of tested samples is calculated by using both curves, confirming the obtained results by two different routes. In this Application Note, comparison between electrochemical and spectroscopic determinations demonstrates that the two methods measure uric acid (UA) indistinctively, with close agreement of the calculated values with empirical data.

In-situ spectroelectrochemistry provides dynamic electrochemical and spectroscopic information concurrently with the redox reaction occurring on the electrode surface. Although different spectroelectrochemical configurations can be used, simple equations explain how to relate electrochemistry and spectroscopy for each experimental setup. This Application Note describes how the quantification of one electrochemical parameter (the diffusion coefficient) is calculated from the spectroscopic data as a proof of this concept.

The development of a novel reflection cell for conventional electrodes facilitates the performance of spectroelectrochemical measurements. This device allows researchers to work in aqueous solutions as well as in organic media due to its chemical resistance.

Poly(3,4-ethylenedioxythiophene) (PEDOT) is one of the most promising ICPs due to its high conductivity, electrochemical stability, catalytic properties, high insolubility in almost all common solvents and interesting electrochromic properties (transparent in the doped state and colored in the neutral state). In this Application Note, PEDOT film is evaluated by spectroelectrochemical techniques.

In this work, time resolved Raman spectroelectrochemistry measurements with screen printed electrodes are shown. The instrument used combines in a totally integrated box: a 785 nm laser source, a high resolution Raman spectrometer and a bipotentiostat/galvanostat. Experiments are controlled with an excellent spectroelectrochemical software which allows real time data collection and useful data treatment.

NIR spectroscopy has been traditionally limited due to the water absorption in this spectral range. In this way, the well-known water restriction has limited the development of new applications for NIR spectroelectrochemistry. In this work, several interesting alternatives are proposed in order to minimize or even to remove the aqueous contribution in this spectral range.