Synchrotron radiation-valence band spectroscopy (SR-VBS) has been utilized in a study of redox molecule valence states implicated in the electron hopping mechanism of ethynylferrocene in unplasticized poly (methyl methacrylate)-poly (decylmethacrylate)[PMMA-PDMA] membranes (Front Cover Electroanalysis 2017, Special Issues, International Conferences of Electrochemical Sensors.
Biogeochemical processes are often confined to very narrow zones in aquatic systems. Therefore, highly resolved in situ measurements are required to study these processes. We fabricated ammonium and pH selective SC-ISEs with functionalized multiwalled carbon nanotubes (f-MWCNT) as a solid contact. Their functionality was tested in the laboratory and applied in situ for vertical profiling in a eutrophic lake. Excellent outcomes from a collaboration with Wherli’s group at ETH Zurich.
Front Cover in Environmental Science and Technology Letters (2017).
We report here on a potentiometric sensing array based on polymeric membrane materials for the continuous monitoring of nutrients and chemical species relevant for the carbon cycle in freshwater ecosystems.
Back Cover in Environmental Science Processes and Impacts (2015)
As a consequence of the Gaston Crespo PhD’s break-grounding results, the use of CNT’s as an ion-to-electron transducer was extended to wearables sensors. Potentiometric all-solid-state ion-selective electrodes using cotton yarns modified with CNT-ink were developed establishing an excellent platform for pH, K+ and NH4+ remote detection. Back Cover, Analyst 2013.
Gaston Crespo and co-workers have devised a system which separates the sample compartment, where the analyte is introduced alongside the ruthenium-based ECL reagent, from the compartment which contains the co-reactant necessary for the chemiluminescence to be generated. HOT paper in Chem. Comm (2011)
This paper is the second one of Gaston’s thesis and brings insightful evidence about the mechanism of carbon nanotubes as ion-to-electron transduction using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV).
Crespo et al., Anal. Chem 2009 has been referenced more than ~150 cites. Outstanding collaboration with Prof. Johan Bobacka! Thanks Johan for sharing your experience with me!
This is lovely paper for so many reasons: i) It was the first paper of Gaston’s PhD; ii) It comes up with a technological revolution in the way that solid-contact sensors were/are now developed; iii) This seminal concept was used in subsequent papers, therefore huge impact (see above); iv) It was published in one the most important journals for analytical chemists such as Anal. Chem. v) It has been cited more than 250 times; vi) Currently, at KTH, we are working with this magnificent material exploring diagnosis and environmental tools. Crespo, et al., Anal Chem, 2008.