Cassasas, who had studied with Prof. I.M. Kolthoff in Minnesota (1954-1955), and had already been Full Professor in the University of La Laguna (1967-1969) and in the Autonomous University of Barcelona (1969-1976), created and directed two research groups in the Department.

The first one was focused on the application of potentiometric and spectrophotometric techniques to the study of solution equilibria and was progressively immersed into the development of chemometrical methods for the analysis and interpretation of data. This was the beginning of the Group of Solution Equilibria and Chemometrics.

The second group was focused on polarograpic and stripping voltammetric techniques, which Prof. Cassasas had studied in Minnesota, and became the Group of Electroanalysis. Once Prof. Casassas retired (1987), Dr. Miquel Esteban (Full professor since 1993) substituted him as the head of the group.

The first research works carried out in the group derived from the Ph.D. Thesis of Miquel Esteban (1984) and Cristina Ariño (1986), both directed by Prof. Casassas, and were devoted to the study of substances with thiol groups and their metal complexes by means of mercury electrodes, where such species present important adsorption phenomena.

Some years later, several stays of Miquel Esteban and José Manuel Díaz (inside the period 1987-1993) in the group of Dr. Herman P. van Leeuwen of the Wageningen University (Netherlands) and the collaboration with Drs. Jaume Puy, Francesc Mas and Josep Galceran from the Physical Chemistry Department of UB and the University of Lleida allowed us to focus the research of the group on the voltammetric study of the metal complexes of polyelectrolites such as synthetic polycarboxylic acids or natural humic and fulvic acids. The Ph.D. of José Manuel Díaz (1992) is the first in the group on this topic, that was also the main goal of the Ph.D. Thesis of Francisco Berbel (2000).

In 1995 the group of Electroanalysis was perfectly stablished, with three staff members (M. Esteban, C. Ariño and J.M. Díaz) plus Prof. Casassas, that was still active as Emeritus Professor, and the incorporation for several years of the visiting professors Bozidar and Zorana Grabaric (from Zagreb, Croacia) and Jesús Mendieta (from the University of Alcalá de Henares). During these years, the collaboration, by one hand, with Dr. Romà Tauler, from the Group of Solution Equilibria and Chemometrics and, by other hand, with Dra Adela Rodríguez, from the Research Institute of Geel (Belgium) stimulated an important reorganisation of the research lines of the group. Thus, we started to apply chemometric techniques of multivariate analysis to the intricate voltammograms (with numerous overlapping signals) obtained in the study of metal binding by thiol-rich proteins. These biomolecules are crucial in the metal regulation of living organisms. The first compounds of this kind to be studied were glutathione (GSH) and methallothioneins (MT), essentially inside the Ph.D. of Sílvia Díaz (2001). Later, the studies were extended to phytochelatins (PC, the biomolecules equivalent to the animal MT in plants) during the Ph.D. of Boris Cruz (2003). The last Ph.D. thesis of the group have insisted on the study of these systems with the incorporation of new experimental techniques to complement the voltammetric information as well as new chemometric methodologies to process non-linear datasets. In this way, the Ph.D. Thesis of Elena Chekmeneva (2009) mainly investigated the use of isothermal titration calorimetry (ITC) and mass spectrometry (ESI-MS), and the Ph.D.Thesis of Arístides Alberich (2011) deals with the application of circular dichroism (CD) and the development of methodologies for correcting the lateral movement of voltammetric signals. Additionally, the Ph.D Thesis of Rui Gusmão (2012) and Santiago Cavanillas (2014) are based upon the use and optimisation of these techniques and methodologies in the case of complex mixtures of metal ions and thiol-rich peptides.

Parallel to the study of metal bioregulators, the development and application of new electrochemical measurement methodologies in the field of metal speciation was also deepened. This is the case of stripping chronopotentiometry (SCP), extensively studied in Núria Serrano's Thesis (2007) and phase-sensitive alternating current polarography (ACP), which was the subject of Anna Garrigosa's Thesis (2010). Also, Núria Serrano and Arístides Alberich began to study the applicability of bismuth film electrodes (on conventional and screen-printed electrodes) in this type of measurements. These studies continued and were extended to antimony films, notably in the framework of Velia Sosa's Thesis (2015). Núria Serrano has investigated the possibilities of Elimination Voltammetry in its linear sweep variant (EVLS) through a collaboration with Dra. Libuse Trnkova, from Masaryk University (Brno, Czech Republic). More recently, he has worked with the group of Dr. Manel del Valle, from the Universitat Autònoma de Barcelona, ​​in the modification of electrodes for use as heavy metal ion sensors and also in the combination of different devices in the form of voltammetric electronic tongues. The subsequent collaboration with Dr. Julio Bastos (who has recently joined the group), with Dr. José María Palacios from the University of Cadiz and with the groups of Drs. Joan de Pablo and Antonio Florido, from the Universitat Politècnica de Catalunya, has allowed nanoparticles to be included in some of the modified electrodes. The Thesis of Clara Pérez-Ràfols (2019) was carried out precisely with the themes of electrode modification and electronic language design. A valuable collaboration has also started with Drs. Rui Gusmão and Zdeněk Sofer, from the University of Chemistry and Technology of Prague (Czech Republic), which was essential in the design of sensors based on screen-printed electrodes modified with 2D materials from the pnictogen group. This collaboration has been concreted above all in María Tapia's Thesis (2023). The applicability of commercial screen-printed electrodes to the monitoring of emerging pollutants (especially organic UV filters and drugs) has also been studied in collaboration with Dra. Silvia Díaz, now a researcher at IDAEA-CSIC in Barcelona). Recently, Jing Huang's Thesis (in progress) has been started and will also continue with the line of development of modified electrodes.

However, the topic of electrochemical detection in liquid chromatography (LC) and flow injection analysis (FIA) has been addressed. The origin of this line of research lies in a research project led by Cristina Ariño that allowed studying the possibilities of voltammetric detection in flow systems with the support of chemometric techniques and using both conventional electrodes and series of ultramicroelectrodes. These investigations were translated into the Thesis of Olga González (2008) and continued with the Thesis of Àngela Dago (2014), which applied the previously investigated methodologies to the LC analysis of synthetic samples and natural extracts of phytochelatins. Among the environmental problems considered are mercury pollution in the mining region of Almadén (investigated with the group of Dr. Pablo Higueras, from the Universidad de Castilla - La Mancha) and in the Ebro River near Flix (investigated with the group of Dr. Sergi Díez, from the IDAEA-CSIC in Barcelona). Regarding methodological developments, the group has designed and patented a flow cell for electrochemical detection with screen-printed electrodes in LC and FIA that is currently commercialized through a non-exclusive license agreement. Recently, a new line of research on food authentication has been started, which is mainly supported by Josep Pagès' Thesis (in progress), where chromatographic techniques play an important role.

One of the last topics we covered is spectroelectrochemistry (SEC), and more generally the combination of optical and electrochemical measurements for the design of hybrid sensing systems. In this field we have the valuable advice of Drs. A. Colinas and A. Heras, from the University of Burgos. We hope that this subject may soon be translated into a Thesis.

Finally, it should be remembered that, despite the fact that the group's research has been structured mainly based on the Doctoral Theses mentioned, an important part of it has also been carried out in the form of shorter stays by people who have completed their Bachelor's Thesis or a Master's. This is the case of Antonia Redondo, Miquel Àngel Benade, Anna Maria Nadal, Dolors Giménez, Marco Argudo, Beatriz Cancho, Marta Torres, Amanda Monjonell, Roger Serra, Maria José López, Mercedes Fernández, Josep Agulló, Carmen de Haro, Elisabet Kapoya, Mar Gómez, Nuria Martín, Ricard Reynaldos, Claudia Gilsanz, Inmaculada González-Sintes, Didac Freixas, Estanislav Mavrin, Núria Cañaveras, Albert González, Javier Navarro, Gabriela Grmanova, Pedro Trechera, Miriam Aragó, Natalia Rojas, Jaume Puy-Llovera, Óscar Castilla, Eva Escriche, Cristina Sánchez, Adrià Sunyer, Miguel Rosal, Alessandra Muschietti, Marc Zaguirre, Javier Marín, Adam Roselló, Ivet Jimènez, Elena Alberto, Gema Bataller, Lluís Otero and Gemma Sagristà.

Nor should we forget the valuable collaborations with researchers who have hosted our PhD students during scientific stays, such as Drs. J. Wang (New Mexico State University, USA), M.L. Simoes Gonçalves and A.M. Almeida Mota (Universidade Técnica de Lisboa, Portugal), I. Sestáková (Heyrovsky Institute, Prague, Czech Republic), G. Scarano (Università di Pisa, Italy), R. Compton (University of Oxford), J.M. Kauffmann (Free University of Brussels), F. Winquist (University of Linköping, Sweden), B. Prieto-Simón (Monash University in Melbourne, Australia, Rovira-Virgili University), G. Crespo (Royal Institute of Technology KTH of Stockholm, Sweden).