Abstract
Le cellule tumorali circolanti (CTCs) stanno attirando crescente attenzione come marker tumorali, in quanto provengono direttamente dai tumori e sono responsabili della progressione metastatica. Il progetto MEET mira a dimostrare la fattibilità di una nuova piattaforma elettrochimica per la rilevazione altamente sensibile di cellule e biomarcatori tumorali. Il sistema combina l'uso di luminofori ultrabright di Ir e Ru con elettrodi 3D nanostrutturati, generando una chemiluminescenza elettrogenerata (ECL) intensa grazie a una reazione con il coreagente. La strategia si basa su tre aspetti fondamentali: (i) progettazione e fabbricazione di elettrodi mesoporosi 3D, (ii) sviluppo di luminofori organometallici ultrabright di Ir, (iii) creazione di una piattaforma elettrochemiluminescente per l’imaging sensibile di microbead e la rilevazione di biomarcatori. L'innovazione proposta offre un controllo spaziale preciso del segnale ECL, con potenziali applicazioni diagnostiche avanzate per l'analisi di singole cellule e la diagnostica del cancro.
Results achieved
The project successfully developed an innovative three-dimensional electrochemiluminescence (ECL) platform based on mesoporous TiO₂ architectures functionalized with phosphonated ruthenium complexes. The research addressed a key challenge in ECL science and imaging, namely the ability to control and understand how the spatial positioning of luminophores within nanostructured electrodes affects light-generation mechanisms and analytical performance. A major achievement of the project was the design and fabrication of a solid-state ECL platform in which the distance between the immobilized ruthenium luminophore and the conductive electrode substrate could be tuned with micrometric precision. This was accomplished through a zirconium-phosphate surface engineering strategy combined with controlled functionalization of mesoporous TiO₂ films. Advanced depth-profiling analyses (ToF-SIMS) demonstrated the possibility of creating vertically graded distributions of luminophores and accurately controlling their confinement within the porous structure. The project provided new mechanistic insights into electrochemiluminescence generation. Electrochemical and electrochemiluminescence investigations demonstrated that catalytic ECL can be sustained even when the luminophore is physically separated from the electrode surface by several micrometres of semiconductor material. The results revealed that the TiO₂ scaffold acts as an electronic mediator, enabling charge transfer between the electrode and the confined ruthenium centres. Systematic variation of the luminophore–electrode distance showed that this parameter directly governs the efficiency and the operative pathway of the ECL process. Increasing the separation progressively reduces electronic communication and modifies the relative contribution of different emission mechanisms. A further important outcome was the identification of an optimized operating regime that preserves luminophore confinement and stability while maintaining efficient catalytic ECL generation. The study demonstrated that appropriate control of the applied potential prevents luminophore desorption and enables reproducible and stable light emission over repeated measurement cycles. Beyond the mechanistic advances, the project established a novel strategy for label-free ECL imaging. The developed platform exploits immobilized luminophores embedded within the porous TiO₂ matrix, while the co-reactant remains freely diffusing in solution. This architecture enabled the realization of shadow ECL microscopy with high spatial contrast, where local perturbations of co-reactant transport generate clearly resolved emission patterns without the need for fluorescent labels. Imaging experiments demonstrated the capability of the platform to resolve micrometric features that are difficult to distinguish by conventional optical observation alone [1]. Overall, the project introduced depth-controlled luminophore confinement as a new design parameter for engineering electrochemiluminescent processes. The results provide a fundamental framework for the rational design of next-generation ECL materials and devices, with potential applications in advanced bioimaging, analytical sensing, electrochemical microscopy, and spatially resolved investigation of interfacial phenomena. The project outcomes have been disseminated through scientific publications, conference presentations, and collaborations involving researchers from the University of Bologna, the University of Catania, and the National Research Council (CNR), contributing to the advancement of electrochemiluminescence research at the international level. [1] C. Mariani et al. Solid-State 3D Electrochemiluminescence Platform: Depth-Tuned Ru Complexes Positioning for Label-Free High-Resolution Imaging ACS Omega 2026, in pressProject details
Unibo Team Leader: Francesco Paolucci
Unibo involved Department/s:
Dipartimento di Chimica "Giacomo Ciamician"
Coordinator:
ALMA MATER STUDIORUM - Università di Bologna(Italy)
Total Eu Contribution: Euro (EUR) 200.000,00
Total Unibo Contribution: Euro (EUR) 70.000,00
Project Duration in months: 24
Start Date:
28/09/2023
End Date:
28/02/2026
