Conquering a New Paradigm for Addressing Ion Detection in Real Scenarios

Project Information

ConquerIons

Grant agreement ID: 851957

DOI

10.3030/851957

EC signature date 2 October 2019

Start date 1 January 2021

End date 31 December 2026

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 605 248,75

EU contribution

€ 1 605 248,75

Coordinated by

FUNDACION UNIVERSITARIA SAN ANTONIO
Spain

Periodic Reporting for period 4 - ConquerIons (Conquering a New Paradigm for Addressing Ion Detection in Real Scenarios)

Reporting period: 2024-04-01 to 2025-09-30

Summary of the context and overall objectives of the project

ConquerIons is seeking a definitive solution for the detection of ions in real scenarios by innovatively addressing the limitations of traditional concepts in terms of effectiveness, sensitiveness, robustness and downscaled platforms. Thus, the project proposes a new generation of electrochemical and optical ion sensors by fundamentally investigating on what we have called as "ion-selective nanomembranes" in tandem with redox mediators. The uniqueness of the dynamic electrochemical tuning of ion-transfer processes across these nanomembranes opens up a revolutionary approach that allows for the monitoring of ion concentration in a sample with unprecedented analytical performance. The project combines efforts from the synthetic chemistry, material science, nanoscience, electrochemistry and analytical chemistry disciplines resulting in a universal concept for the reliable detection of ions. ConquerIons is based on a research approach that mainly considers the following challenges: (i) the use of novel materials to afford a robust and universal ions’ detection; (ii) the implementation of thin-layer concepts to achieve reduced limits of detection and calibration-free methodology; (iii) the translation of the developed sensing concepts to the single-entity scale; and (iv) exploitation of sensors at the laboratory context considering cases that are relevant to the society. Regarding the latter, successful proof-of-concepts in the project cover EU priorities related to “citizens’ welfare” and “protecting nature”, aiming to enhance EU excellence and competitiveness in healthcare and water issues through reliable and decentralized chemical digitalization. Moreover, in a long-term perspective, the project outcomes would find an application niche in challenging analytical applications such as cell-scale therapies in clinical research as well as speciation of trace ion levels in environmental analysis.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The main scientific achievements reached in the first half of the project have been:
1) Electrochemical and optical ion sensors whose architecture fundaments on two main interconnected elements: the redox mediator and the nanomembrane. For the redox mediator, a series of lipophilic metallic compounds and conducting polymers have been synthetized and investigated, with the main outcomes highlighting the suitability of a newly synthetized osmium-based compound. For the nanomembrane, the project has researched on materials, composition and the modelling of the working mechanism, which is essentially based on a series of interconnected charge-transfer processes. The main results demonstrated the robust and reversible detection of different ions, with unusually wide analytical range of response.
2) The project has investigated the electrochemical protocol to interrogate the sensors and the corresponding electrochemical and optical readouts. The improvement of the limit of detection has been demonstrated.
3) Spectroelectrochemistry has been proved as an excellent vehicle for both mechanistical studies and better exploitation of the analytical performance of the sensors.
4) The project is now researching on the integration of thin-layer samples together with the mediator-nanomembrane tandem towards calibration-free sensors.
5) The mediator-nanomembrane tandem has been preliminarily translated to the nanoparticle format, being characterized under light-driven conditions.
6) Some cases of exploitation of the ion sensors at the laboratory scale have been achieved. Potassium, sodium, silver, copper, lead, chloride and phosphate ions have been determined in certain artificial clinical samples, as well as commercially available products and environmental waters.
7) It has been discovered that the nanomembranes can be implemented in the format of nanosensors for extra- and intra-cellular measurements, and for the selective ion capturing in complex matrix samples to reduce influence of ionic interferences in the electrochemical readout. In the case of the redox mediator, it has been found that certain conducting polymers can be utilized as solid acidifiers of samples, since their structures include exchangeable hydrogen ions. This capability has been implemented in sensor-actuator systems for the imaging of environmental processes.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

ConquerIons puts forward innovative sensing strategies for the universal detection of ions in real scenarios. On the fundamental basis of ion-transfer processes across nanometer-sized ion-selective membranes, the project builds upon a new generation of ion sensors with superior features that overcome all the drawbacks of conventional ion sensors. The significance of this project relies on leaving the comfort zone concerning the interrogation mode of traditional ion-selective electrodes by means of a completely different approach based on tuned ion transport across the membrane, which is triggered by the charge imbalance of custom-made redox nanomaterials. Dynamic electrochemistry protocols coupled to coulometry or optical output will satisfy the current need for ion sensing in the intermesh of sensitivity, cross-selectivity and robustness, which has no precedent today. In addition, the culmination of the exploitation of the novel strategy is foreseen to be demonstrated at the single-entity level, referring to ion transfer events in only one nanoparticle. The project has already demonstrated notable innovation beyond the state of the art, placing the mediator-nanomembrane technology on the top of current strategies for chemical digitalization. Moreover, the unique combination of materials and electrochemically controlled mechanisms herein proposed has led to the tangible proof that certain societal challenges involving ions’ detection can be successfully addressed. Yet, the final exploitation of the fundamental outcomes is to be demonstrated, contributing to future action to improve the EU social welfare but also, collecting relevant information to understand EU aquatic systems. Altogether, this project aims to provide a series of reliable analytical tools to protect ecosystems and human health assuring a sustainable development (EU policy and legislation) as well as prevention of economic losses.

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