Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Janine Mauzeroll, PhD
Professor of Chemistry
Department of Chemistry
McGill University
The Wonderful World of
Scanning Electrochemical
Microscopy (SECM)

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
The Wonderful World of
Scanning Electrochemical
Microscopy (SECM)
Dr. Janine Mauzeroll discusses the
fundamentals, critical experimental
parameters and recent applications for
Scanning Electrochemical Microscopy (SECM).

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Janine Mauzeroll, PhD
Professor of Chemistry
Department of Chemistry
McGill University
The Wonderful World of
Scanning Electrochemical
Microscopy (SECM)
Copyright 2021 J. Mauzeroll and InsideScientific. All Rights Reserved.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Piled Higher and Deeper by Jorge Cham www.phdcomics.com
title: "Thesis writing" - originally published 11/5/1999
4
Strange what also applies to talks…..

Laboratory for Electrochemical Reactive
Imaging of Biological Systems

Laboratory for Electrochemical Reactive
Imaging of Biological Systems 6
Janine Mauzeroll
Today is all About…

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Bulk Diffusion
Feedback mode
(Insulating surface)
Feedback mode
(Conductive surface)
Substrate generation –
tip collection
Tip generation –
substrate collection
Redox competition Direct mode Potentiometric
mode
7
Janine Mauzeroll
Modes of SECM

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
x
z
y
8
Janine Mauzeroll
Scanning Electrochemical Microscope

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
• The rate of electrochemical reactions (v) is monitored through
currents measured at the microelectrode (i).
• We can study the substrate’s electrochemical reactivity in this way.
9
Janine Mauzeroll
SECM Principle

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
• In electrochemistry, we control ΔGRXN using Eapplied
Product
Reactant
Oxidation A A+ + e
Transition
State
10
Janine Mauzeroll
Controlling Charge Transfer

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
v = Rate of electrochemical reactions
i = Microelectrode currents
n = # of electrons
F = Faraday’s constant
A = electrode area
1) Rate of electron transfer
2) Rate of mass transport
11
Janine Mauzeroll
What Do I Need to Know to Quantify the Current?

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
F = Faraday’s constant
A = Electrode area
k0 = Standard rate constant
CO(0,t) ; CR(0,t) = Surface concentrations of species O,R
α = Transfer coefficient
E – E0’ = Overpotential (driving force applied)
12
Janine Mauzeroll
• Reaction kinetics at an electrode
surface follow the Butler-Volmer
relationship
Heterogeneous Electron Transfer Rate

Laboratory for Electrochemical Reactive
Imaging of Biological Systems 13
Janine Mauzeroll
Mass Transport in the Electrolyte

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Mass transport in electrolyte
Electrode kinetics
Butler-Volmer:
First order kinetics:
Concentration boundaries
14
Janine Mauzeroll
Finite Element Modeling is Required in SECM

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Normalized Electrode current is a function of L, Rg, κ
κ
C. Lefrou and R. Cornut, ChemPhysChem, 11, 547 (2010)
Probe Approach Curve Analytical Approximations

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Positive FB
Negative FB
16
Janine Mauzeroll
Tracking Substrate Reactivity using SECM

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Red Ox
L (tip-substrate distance)
NiT (tip current)
e-
e-
17
Janine Mauzeroll
Substrates with Finite Kinetics

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Classical Probes
Multifunctional Probes
Danis, L.; Mauzeroll, J. et. al.
Anal. Chem. 2015. p 2565
Danis, L.; Mauzeroll, J. et. al.
Anal. Chem. 2015. p 2565
Katemann, B. B.; Schuhmann W.
ElectroAnalysis 2002. p 22
Walsh, D. A.; Bard, A. J.; et. al.
Anal. Chem. 2005. p 5182

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Polcari, D.; Dauphin-Ducharme, P.; Mauzeroll J., Chem. Rev., 116, 13234 (2016)
Application Fields of SECM

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
 Cancer Cells
 Batteries
 Corrosion
20
Janine Mauzeroll
Three Short Stories

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Expression and Functional Activity of Multidrug
Resistance-Associated Protein 1 using SECM
Polcari, D.; Mauzeroll, J. et al., Anal. Chem., 89, 8988 (2017).
Kuss, S.; Mauzeroll, J. et al., Anal. Chem., 87, 8096 (2015).
Kuss, S.; Mauzeroll, J. et al., Anal. Chem., 87, 8102 (2015).
Kuss1, Polcari1 et al., PNAS 110, 9249 (2013)

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Drug-Sensitive Cancer Cell
(Ex: HeLa Cells)
Multidrug Resistant Cancer Cell
(Ex: HeLa-R Cells)
22
Janine Mauzeroll
Multidrug Resistance (MDR)

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Drug-Sensitive Cancer Cell
(Ex: HeLa Cells)
MDR Cancer Cell
(Ex: HeLa-R Cells)
0.05 µM 0.10 µM
Untreated 0.05 µM 0.10 µM
Untreated
Drug Challenge
Janine Mauzeroll 25

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Cell Patterning for SECM
Janine Mauzeroll 24

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
No Interaction  Negative Feedback
Diffusion into Cell  Positive Feedback
Measuring MRP1 Activity
Janine Mauzeroll 25

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
• Extract tip to substrate distance, L,
at each image pixel
• Then extract heterogeneous kinetics , κ,
at each image pixel
Two Step Process Convolution
Janine Mauzeroll 26

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
(cm
s
-1
)
Effect of Pattern Size
Polcari, D.; Mauzeroll, J. et al., Anal. Chem., 89, 8988 (2017)

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
(cm
s
-1
)
Time-Lapse Imaging
Polcari, D.; Mauzeroll, J. et al., Anal. Chem., 89, 8988 (2017)

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Polcari, D.; Mauzeroll, J. et al., Anal. Chem., 89, 8988 (2017)
Activity of Six Different Cell Populations

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
 Cancer Cells
 Batteries
 Corrosion
30
Janine Mauzeroll
Three Short Stories

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Localized Investigations of the Electrochemical
Properties of Lithium Battery Materials Using
Micropipette
Dayeh, M.; Snowden, M. E.; Ghavidel, M.; Payne, N.;
Gervais, S.; Mauzeroll, J.; Schougaard, S. B.
Journal of Power Sources 2016, 325, 682-689.
ChemElectroChem, 2019, 6, 195–201
Analytical Chemistry 2019, 91(24), 15718-15725
Analytical Chemistry 2020, 92, 10908-10912.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Malak Dayeh
1 μm 1 μm
1 μm
Are all battery particles created equal?
32

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
20 µm
Single particle battery
Measuring Isolated Active Particles
33

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2
-400
-200
0
200
400
600
i
(pA)
E (V) vs. Li/Li+
distance (μm)
i
(μA)
distance (μm)
i
(μA)
Approach
Land
Retract
Measure
Scanning Micropipette Contact Method
34

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2
-400
-200
0
200
400
600
i
(pA)
E (V) vs. Li/Li+
distance (μm)
i
(μA)
distance (μm)
i
(μA)
Approach
Land
Retract
Measure
Scanning Micropipette Contact Method
35

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Malak Dayeh
- Very low water and oxygen content (~ 1 ppm)
- The only gas present is Argon
Electrode
Pipette
Substrate
Development of SMCM in
Anaerobic Conditions
36

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Malak Dayeh
2μm
Journal of Power Sources 2016, 325, 682–689.
LiFePO4 Li+ + e- + FePO4
2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2
-20
-10
0
10
20 1 mV/s
5 mV/s
10 mV/s
20 mV/s
50 mV/s
Potential / V (vs. Li/Li+
)
Current
/
p
A
Epf
ipf
2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2
-600
-400
-200
0
200
400
600
Current
/
p
A
Potential / V (vs. Li/Li+
)
SMCM on Isolated LiFePO4 Active Particles

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Electrochemistry and Electron Microscopy
Malak Dayeh
0 1 2 3 4 5 6 7
0
10
20
30
40
Particle Area (µm2
)
i
pf
(pA)
0.0
0.4
0.8
1.2
1.6
2.0
Q
f
(nC)
- Particle cross section areas obtained from SEM are compared to the forward (oxidation) peak
current and the integrated charge.
- A larger cross section area correlates to both a higher peak current and increased charge.
LiFePO4 Li+ + e- + FePO4
Journal of Power Sources 2016, 325, 682–689.
38

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
2 µm
i
2 µm
iii
2 µm
ii
Malak Dayeh
6%
27%
67%
0 100
Shifted
peak
Double
peak
Single
peak
Differences in
electrochemical
performances
Journal of Power Sources 2016, 325, 682–689.
Particles’ Heterogeneities

Laboratory for Electrochemical Reactive
Imaging of Biological Systems 40
Malak Dayeh
Summary
SMCM technique is:
Valuable tool for probing the localized electroactivity of
battery active material
Capable of detecting heterogeneity in material properties
distribution
❌Considered as a quality control tool for active material
fabrication, and monitoring batch-to-batch variations in
particle properties
� Particle volume still evaluated by external means

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Malak Dayeh
Future Direction: Two Diffusion Regimes
Journal of Power Sources 2010, 195(24), 7904-7929.
Li+
LFP
1
2
LiFePO4 Li+ + e- + FePO4
1: Transport of Li+ ions in electrolyte
2: Diffusion of Li+ ions within LFP particle

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Use SICM to measure porous film conductivity
Analytical Chemistry 2019, 91(24), 15718-15725

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
A composite cathode is a porous film
Analytical Chemistry 2019, 91(24), 15718-15725

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
SICM approach curve= film conductivity
Analytical Chemistry 2019, 91(24), 15718-15725

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
From Macro to Micro: Using Electrochemical
Methods to Investigate the Effect of Alloy
Chemistry on Corrosion
Gateman, S.M.; Stephens, L.I.; Perry, S.C.; Lacasse, R.; Schulz, R.;
Mauzeroll, J.
Nature Materials Degradation 2018, 2, 1-8.
Nature Materials Degradation 2019, 3, 25.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
1. Stainless Steels have inclusions promoting corrosion
Janine Mauzeroll
Elemental Composition of SS 444
Fe Cr Mo Si Ni Nb Mn V Cu Ti
Supplier’s
Claim
79.9 17.07 1.89 0.17 0.24 0.307 0.28 0.1
1
0.063 0.15
Experimental
ICP-OES
79.54 17.3 1.93 -- 0.25 -- 0.3 0.1
1
0.08 --
Gateman, S. M., et al., npj Mater. Degrad, 2018, 2, 5.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Extracting Kinetic Rate Constants Using FEM
Janine Mauzeroll
2.85 x 10-2 cm/s
0.2 x 10-2 cm/s
Gateman, S. M., et al., npj Mater. Degrad, 2018, 2, 5.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
SS 444 is extremely corrosion resistant according to ASTM
standard PDP measurements, but is vulnerable to
localized corrosion.
Gathered experimental and theoretical evidence of a
microgalvanic coupling effect between the Ti/Nb rich
inclusions/precipitates and the surrounding metal matrix.
1. Conclusions
Janine Mauzeroll
1 cm
Gateman, S. M., et al., npj Mater. Degrad, 2018, 2, 5.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
2. HVOF Thermal Spray Coatings Corrosion?
Janine Mauzeroll
T= ~2000 K
100 µm
100 µm
Struers, 2005, Metallographic
preparation of thermal spray coatings

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Tafel Analysis of Coatings: Active Corrosion
All tests were performed in 3.5 wt% NaCl at a scan rate of 0.167 mV/s. All coatings are
tested as received without the use of grinding/ polishing.
Janine Mauzeroll
Scan direction
Ecorr Anodic
Cathodic
Anodic
Cathodic
Gateman, S. M., et al., npj Mater. Degrad, 2018, 2, 5.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Scanning Electrochemical Microscopy: Feedback Mode
Insulating substrate = Topography
Conductive Substrate = Topography + Reactivity
Insulator
Conductor
Janine Mauzeroll 61
X

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Minimal Passivation Detected using SECM
Janine Mauzeroll Gateman, S. M., et al., npj Mater. Degrad, 2018, 2, 5.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Micro Polarization of a Single Powder Particle
Janine Mauzeroll Gateman, S. M., et al., npj Mater. Degrad, 2018, 2, 5.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Linked the stainless steel thermal spray coating’s weak
corrosion resistance to the precursor powder
Identified regions of vulnerability across a single powder
particle using scanning electrochemical probe methods
Highlighted the power of using macro and micro
electrochemical methods to characterize load bearing
materials
Showcased the importance of powder metallurgy in
coating technologies
2. Conclusions
Janine Mauzeroll 54

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Janine Mauzeroll 55
Mineral oil:
 Insulating
 Hydrophobic
 Colorless
OI-SMCM
3. Oil-Immersed Scanning Micropipette Contact Method

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Janine Mauzeroll
Mineral Oil Reduces Background Noise
2.2 pA in air
5.2 pA in humidified cell
1.35 pA in mineral oil
Background
noise
(pA)
Time
Current
Threshold
Time
A low background noise will reduce the risk of breaking
micropipette when landing.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Janine Mauzeroll 57
OI-SMCM Ecorr Map Reveals Microscale Heterogeneities
20 μm
Al
20 μm
Fe
20 μm

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Janine Mauzeroll 58
Predict Galvanic Couples
610
608
5 μm
Fe-rich inclusion exhibits cathodic behavior relative to the Al
matrix area, which implies the surrounding Al will be consumed
as the anode in the galvanic couple with the inclusion.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Janine Mauzeroll 59
OI-SMCM Icorr Map Exhibits Microscale Corrosion Kinetics
20 μm

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Janine Mauzeroll 60
Microgalvanic Corrosion
13
12
30
29
Galvanic couples
Oxygen reduction on inclusion surface: cathodic branch (13 and 30).
Surrounding Al dissolution: the anodic branch (12 and 29).
Ecorr at the meeting points are more anodic relative to that of Al
matrix.
Therefore, the Al surrounding the Fe-rich inclusions is more
susceptible to corrosion.

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
3. Conclusions
Janine Mauzeroll 61
Oil-Immersed SMCM:
 Allows for the use of highly evaporative electrolyte
solutions
 Long-time stability for a large map
 Expands the application of SMCM

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Acknowledgements
62
Janine Mauzeroll

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
Corrosion
Cancer Cells
Batteries
Spectroelectrochemistry
Catalysis
Biofilms
Enzyme Films
Polymer Films
Janine Mauzeroll
Final Thoughts…
63

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
THANK YOU TO MY
64
Janine Mauzeroll

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
BSc
(30)
Meng, B; Potts, K.; Robert, A.;
Lin M., Sifakis, J.; Gordon, J.
Chen, Y. ; Gateman, S.
Langlois-T., T; .Sangji, H.
Boudreau, C.; Vassileva, I.
Wei, X.; Mack, T.
Salvatore, D.; Kwan, A.
Yong, K.; St-Pierre, C.
Poirier, S.; Wezel, N.
Meyrignac, P.; Fabre, D.
Joliton, A.; Gariepy, V.
Bavencove, A.; Benlounes, K.
Dansereau, D.; Tieu, J.
Noel, J.; Pierre, J.
MSc/PhD
(18)
Dawkins, J.; Li, Y; Pan,
Y.; Moussa, S.
Odette, W.; Dayeh, M.
Danis, A.; Payne, N.
Mazurkiewicz, S.
Polcari, D;
Dauphin D., P.
Danis, L.; Kuss, S.
Mezour, A.;
Mayoral, M.
Beaulieu, I; Correia, L
Lukova, N.
PDF
(8)
Ghavidel, R.
Perry, S.
Noyhouzer, T.
Kuss, C
Snowden, M.
Mengesha , U.
Thrin, D.
Cornut, R.
Collaborators
(15)
S. Canesi (UQAM)
B Kraatz (UofT)
I. Halalay (GM)
E. Ruthazer, (McGill)
H. Sleiman, (McGill)
M. Geissler (NRC)
D. Bélanger (UQÀM)
M. Lafleur (UdeM)
M. Morin (UQÀM),
S. Schougaard (UQÀM)
D. Shoesmith, (UWO)
G. Botton, (McMaster)
R. Lacasse, (HQ)
R. Schulz, (HQ)
C. Heineman (HEKA)

Laboratory for Electrochemical Reactive
Imaging of Biological Systems
To Companies, Funding Agencies & Universities
$$ $$
Discovery, CRD
Strategic, Create &
UFA
Nouveau Chercheur
& Équipes
$$

Laboratory for Electrochemical Reactive
Imaging of Biological Systems Janine Mauzeroll

Thanks for participating!
• Watch the webinar here:
The Wonderful World of Scanning
Electrochemical Microscopy
• Want to learn more about the technology?
Visit: www.elproscan.com