Abstract
Il progetto MEET mira a sviluppare una tecnologia avanzata di elettrochimiluminescenza (ECL) per rilevare biomarcatori a concentrazioni ultra-basse (picomolare o inferiore) e migliorare la microscopia ECL per l'imaging a livello di singola cellula. L'ECL, un'emissione indotta elettrochimicamente, offre un elevato rapporto segnale-rumore ma è limitata dalla stabilità dei radicali e dall'efficienza dell'emissione. MEET migliorerà l'ECL attraverso la tecnologia Metal Enhanced Electrochemiluminescence, utilizzando nanoparticelle di metalli nobili (Ag, Au) per amplificare l'interazione con i luminofori tramite plasmoni di superficie. L'ottimizzazione delle proprietà delle nanoparticelle e il controllo della durata dei radicali raffineranno lo strato attivo ECL, migliorando la risoluzione spaziale e permettendo il primo microscopio a super-risoluzione basato su ECL. Questa innovazione porterà a nuovi metodi di quantificazione dei biomarcatori e a biosensori di nuova generazione, supportati da un team di ricerca multidisciplinare. Final Results: The MEET project achieved its main planned objectives by developing and validating advanced electrochemiluminescence (ECL)-based materials and protocols for ultrasensitive bioanalysis and single-cell imaging. The project focused on improving ECL signal generation through plasmonic nanomaterials and optimized co-reactant chemistry, with the final aim of enabling highly sensitive detection of biological markers and cells. A broad library of dye-doped plasmonic core-shell nanoparticles was successfully synthesized and characterized. Silver- and gold-based nanostructures with different morphologies, including nanospheres, nanostars, nanorods and triangular silver nanoplates, were prepared using modified silica-coating procedures and functionalized with Ru(bpy)32+-based luminophores. Their structural, optical and ECL properties were systematically investigated, providing new insight into how core composition, morphology, silica-shell architecture and luminophore loading influence emission efficiency. Among the tested systems, plasmonic nanostructures showed relevant signal-enhancement potential, with Au nanorod-based constructs giving the highest integrated ECL response under the selected electrochemical conditions. The project also delivered important advances in the control of ECL generation. A systematic study of co-reactants was carried out using Ru-labelled magnetic microbeads as model emitters. ECL microscopy combined with finite-element simulations made it possible to correlate emission intensity and spatial extension with radical-cation lifetime and molecular structure. This provided a rational framework for selecting ECL conditions and for controlling the ECL-active layer, a key requirement for reliable bead-based assays and high-resolution imaging. Substantial progress was achieved in the development of bead-based analytical platforms. Although the originally planned FeOx/Au magnetic-plasmonic nanostructures did not provide the robustness required for routine biosensor implementation, the project successfully redirected this activity toward commercial streptavidin-coated magnetic microbeads. This alternative platform ensured stable magnetic handling, reproducible biotin-streptavidin functionalization and reliable positioning at the electrode surface. Optimized electrode preparation, magnetic capture, washing procedures, co-reactant delivery and electrochemical parameters led to a reproducible assay workflow. The most significant analytical result was the implementation of a sandwich-type ECL immunoassay for the detection of epithelial cells, used as a model for circulating tumor cells. The assay combined antibody-mediated magnetic capture with Ru(bpy)32+-labelled detection and was adapted to both bulk ECL readout and ECL microscopy. The platform enabled quantitative detection at very low cell concentrations, reaching a limit of detection of approximately 11 cells/mL. ECL microscopy further demonstrated single-cell-level detection, supported by co-registered optical/photoluminescence and ECL images that allowed direct localization of emissive bead-cell aggregates and discrimination from background signals. A signal enhancement of about seven-fold over reference samples was also demonstrated in the single-cell imaging configuration. All planned deliverables across WP1, WP2 and WP3 were completed. The project produced open-access scientific outputs, disseminated results through international conferences, lectures, workshops and collaborative meetings, and complied with DNSH, Open Access, gender, generational and equal-opportunity principles. Overall, MEET provides a solid proof of concept for next-generation ECL biosensing and imaging platforms. The results establish a strong basis for future applications, clinically relevant samples such as whole-blood circulating tumor cell detection, multiplexed biomarker analysis, microfluidic integration and further nanoparticle-based signal amplification.
Dettagli del progetto
Responsabile scientifico: Giovanni Valenti
Strutture Unibo coinvolte:
Dipartimento di Chimica "Giacomo Ciamician"
Coordinatore:
ALMA MATER STUDIORUM - Università di Bologna(Italy)
Contributo totale di progetto: Euro (EUR) 222.260,00
Contributo totale Unibo: Euro (EUR) 112.260,00
Durata del progetto in mesi: 27
Data di inizio
30/11/2023
Data di fine:
28/02/2026
