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Intitulé du sujet: Pushing the detection limit in nanoelectrochemistry via a current-to-photon conversion scheme using electrochemiluminescence : Application to ultrafast single nanoparticle collision detection

Sujet

Codirection: non

Nombre de mois: 48 mois

Ecole Doctorale: ED 388 - Chimie physique et Chimie analytique de Paris centre

Unité de recherche et équipe:

Laboratory « Interfaces Traitements Organisation et DYnamique des Systèmes » (ITODYS), UMR CNRS 7086, Université Paris Cité. BioNano group (Christophe Demaille and Arnaud Chovin)

Coordonnées de l’équipe:

ITODYS-Université Paris Cité, batiment LAVOISIER, 15 Rue Jean Antoine de Baif, 75013 Paris  

Secteur: Sciences Physiques et Ingénierie / Physical sciences and Engineering

Langue attendue: Anglais

Niveau de langue attendu: B2

Description

Description du sujet:

  1. Scientific context of the PhD subject 

A modern approach to “single entity“ electrochemistry is the so-called nano-impact method, in which individual (bio)particles collide or adsorb randomly on an ultramicroelectrode (UME), generating a series of discernible transient current signatures (step- or spike-like) above the current baseline.1-5 Resolving the very fast and low intensity electrochemical signals associated with these collision “events” is a daunting challenge in nanoelectrochemistry, calling for new disruptive instrumental approaches.6-8 Conventional detection of the (faradaic) current generated by the nanoparticles impacts, based on a purely amperometric readout, are severely limited by the concomitant lack of sensitivity and temporal resolution (slow response time) of electronics in the “ultra-low” current scales.9 New schemes coupling electrochemistry and fluorescence have recently emerged as a transformative strategy to transduce discrete electrochemical events into a more easily detectable light emission.6,10,11 In this vein, our group has developed the first universal opto-electrochemical platform enabling any electrochemical process occurring at an UME surface to be quantitavely convert into a remote, and simultaneous, fluorescence readout.12,13 We now intent to demonstrate that these instrumental scheme can be adapted for resolving in time collisions of nanoparticles with an UME, by turning to electrochemiluminescence as reporting signal.

  1. Objectives of the proposal

Electrochemiluminescence (or ECL) refers to light emission phenomena confined at the surface of an electrode, initiated by an electron transfer reaction that ends with the local production of a molecule in its excited (luminescent) state.14 Using the classical luminophore/co-reactant systems, ECL provides a simple, yet highly sensitive, visual output usable for many (bio)analytical and imaging applications, now pushed to the scale of the single nano-entity.15,16 In addition, the very fast radiative decay of the luminophore confers to ECL a de facto greatly reduced spatial and temporal extent of the light signal, and therefore a rapid "optical" response.17

 The aim of the PhD proposal is to implement ECL and its inherent analytical advantages to our potentiostatic current-to-light convertion scheme, previously deployed with electro-fluorogenic systems.12,13 This will imply delineating the optimal opto- electrochemical configuration enabling the most sensitive and better time-resolved sensing, notably by the fabrication of novel transparent UMEs, and by studying the performances of various ECL reactions used as the light generation mechanism. This should allow to push further the limits of both the sensitivity and time bandwidth of detection, enabling to “optically” capture the full dynamics of nanoparticle collisions with an UME, without any electronics-induced distortions.3,17 Two relevant systems will be considered : 1. platinum nanoparticles catalyzing proton reduction, resulting in the production of dihydrogen,18 and 2. silver nanoparticles undergoing oxidative dissolution.4,17 Application to the electrochemical detection of single biological entities (i.e. enzymes) is also envisioned.8, 19

  1. Impacts and benefits of the project

This project addresses the issue of the ultimate limit of detection in electrochemistry, in terms of current sensitivity (in the sub-picoamp range) and concomitant temporal resolution. Our original approach opens up a new path to advanced systems for measuring electrochemical events at very low current scales, eagerly awaited by bio- and nano-electrochemists who are currently constrained by instrumental limitations. Regarding its novelty and importance, the results produced in this project will be publishable in high impact journal. As single-entity analysis methods have become the forefront of (bio)analytical chemistry, our contribution will undoubtedly help the community developing ultra-sensitive “digital” (bio)sensing platforms.

Compétences requises:

Profile : Candidate at M2 research level - Engineer, or equivalent diploma. Training in chemistry, nano-chemistry and analytical chemistry. Experience in electrochemistry, microscopy or instrumental development desirable. Open to interdisciplinary approaches.

Keywords: nanoelectrochemistry, nanoparticle, ultramicroelectrode, opto-electrochemical platforms, electrochemiluminescence (ECL), electrocatalysis

Références bibliographiques:

  1. Baker L.A. “Perspective and prospectus on single-entity electrochemistry” J. Am. Chem. Soc. 2018, 140, 15549
  2. Goines S., Dick J. E. “Review. Electrochemistry’s potential to reach the ultimate sensitivity in measurement science” J. Electrochem. Soc. 2020, 167, 37505
  3. Sokolov S. V., Eloul S. Kätelhön E., Batchelor-McAuley C., Compton R. G. “Electrode-particle impacts: a user’s guide” Phys. Chem. Chem. Phys. 2017, 19, 28
  4. Defnet P. A., Anderson T. J., Zhang B. “Stochastic collision electrochemistry of single silver nanoparticles”. Curr. Opin. Electrochem. 2020, 22, 129
  5. Peng M., Zhou Y-G. “Impact electrochemical analysis of soft bio-particles : a mini review” Electrochem. Commun. 2023, 150, 107490
  6. Mathwig K., Aartsma T. J., Canters G. W., Lemay S. G. “Nanoscale methods for single-molecule electrochemistry” Annu. Rev. Anal. Chem. 2014, 7, 383
  7. Edwards M. A., Robinson D. A., Ren H., Cheyne C. G., Tan C. S., White H. S. “Nanoscale electrochemical kinetics and dynamics: the challenges and opportunities of single-entity measurements” Faraday Discuss. 2018, 210, 9
  8. Chovin A., Demaille C., Paiva T. O. “When nanoelectrochemistry meet biocatalysis” Curr. Opin. Electrochem. 2023, 40, 101346
  9. Gao R., Edwards M. A., Harris J. M., White H. S. “Shot noise sets the limit of quantification in electrochemical measurements” Curr. Opin. Electrochem. 2020, 22, 170
  10. Fan Y., Hao R., Han C., Zhang B. “Counting single redox molecules in a nanoscale electrochemical cell” Anal.Chem. 2018, 90, 13837
  11. Jeuken L., Orrit M., Canters G. “Single-molecule fluorescence in redox chemistry” Curr. Opin. Electrochem. 2023, 37, 101196
  12. Djoumer R., Anne A., Chovin A., Demaille C. Dejous C., Hallil H., Lachaud J-L. “Converting any faradaic current generated at an electrode under potentiostatic control into a remote fluorescence signal” Anal. Chem. 2019, 91, 6775 
  13. Djoumer R., Chovin A., Demaille C. Dejous C., Hallil H. “Real-time conversion of electrochemical currents into fluorescence signals using 8-Hydroxypyrene-1,3,6-trisulfonic acid (HPTS) and amplex red as fluorogenic reporters” ChemElectroChem 2021, 8, 2298
  14. Liu Z., Qi W., Xu G. “Recent advances in electrochemiluminescence” Chem. Soc. Rev. 2015, 44, 3117
  15. Zhao W., Chen H-Y., Xu J-J. “Electrogenerated chemiluminescence detection of single entities” Chem. Sci. 2021, 12, 5720
  16. Knezevic S., Bouffier L., Liu B., Jiang D., Sojic N. “Electrochemiluminescence microcopy: from single objects to living cells” Curr. Opin. Electrochem. 2022, 35, 101096
  17. Robinson D. A., Edwards M. A., Ren H., White H. S. “Effects of instrumental filters on electrochemical measurement of single-nanoparticles collision dynamics” ChemElectroChem 2018, 5, 3059
  18. Defnet P. A., Han C., Zhang B. “temporally-resolved ultrafast hydrogen adsorption and evolution on single platinum nanoparticles” Anal. Chem. 2019, 91, 4023
  19. Shen X., Liu R., Wang D. “Nanoconfined electrochemical collision and catalysis of single enzyme inside carbon nanopipettes” Anal. Chem. 2022, 94, 8110