Investigation domain
MicroElectrochemical sensors – In vitro diagnostic –Microfluidics
Microdevices for the analysis of the embryo development

Context of the project:
Oxidative stress reflects an imbalance between the intracellular production of reactive oxygen
(ROS) such as hydrogen peroxide (H2O2) and nitrogen (RNS) species such as nitric oxide (NO)
and a biological system’s ability to eliminate these reactive intermediates. These short-lived
species have beneficial or deleterious effects, notably depending on their in vivo levels.

In the context of embryo development and the use of assisted reproductive technologies, oxidative
stress appears to be one of the major factors affecting the success rate of embryonic
biotechnologies. It impacts the long-term phenotype of individuals born from these
biotechnologies. The monitoring of ROS and RNS is thus of outmost importance to find better
embryo development conditions. The measurement of the production of ROS/RNS faces major
difficulties: these species are involved in several cellular mechanisms, they are unstable and
their level is generally low.
Objectives of the project
In this context, we propose the conception of microdevices with incorporated
electrochemical sensors with and without microfluidics, for the real-time extra-cellular
measurement of ROS and RNS releases to closely monitor the embryo activity. The evaluation of
ROS and RNS will be achieved by designing miniaturized sensors implemented inside
microdevices to selectively detect the targeted analytes (ROS and RNS) in vitro for several
days (pre-implantation period of embryo).
Post-doctoral position
The post-doctoral position will be granted by the ANR (France).
The candidate will be involved in a multi-disciplinary project that will be conducted in a
consortium of three laboratories described below, localized in the center of Paris and at Jouy en
Josas. The candidate will develop microdevices with the incorporation of microelectrodes with
different designs devoted to the simultaneous detection of ROS and RNS, during in vitro embryo
development. The challenge will be to perform the simultaneous selective detection of several
reactive species, that will be present at trace level: H2O2, NO and O2−, with particular attention to
sensitivity and selectivity for their detection in embryo culture media. The development of
biocompatible devices/materials is also essential since the embryos will be cultured within the
devices for a few days. The electrochemical sensors will be integrated into small wells or
microstructures and/or inside microchannels of microfluidic devices and will be used underflow
to mimic in vivo conditions of embryo development. The candidate will strongly interact with the
UMR1198 for the application of the devices to the analysis of redox stress markers at the level of
several embryos and then at the level of a unique embryo. It should be noted that the UMR1198
will develop in parallel measurements of intracellular ROS/RNS using fluorescent probes and
evaluate oxidative stress-related genes expression.
The preparation of selective electrochemical sensors for ROS and RNS analysis will be
performed at iCLeHS (Chimie ParisTech), while the microelectrode preparation and microfluidic
devices assembly will be designed at UMR PASTEUR (Ecole Normale Supérieure). The devices
are devoted to the analysis of embryos culture media so that the post-doctorate will strongly
interact with UMR 1198 (INRAE), specialized in embryo biology research.
Profile of the candidate:
The candidate should have a PhD in analytical chemistry or electrochemistry, with research
expertises in electroanalysis, electrode surface modification, an attraction for chemistry/biology
interdisciplinary project, and also experimental basic knowledge in micro-fabrication
technologies.
Practical Informations :
Beginning schedule: October 2020
Duration: 18 months
Involved laboratories:
§ Chimie ParisTech (ENSCP), Institute of Chemistry for Health and Life Sciences CNRS
2027 (iCLeHS), Paris.
§ École Normale Supérieure (ENS), Laboratoire PASTEUR, UMR CNRS 8640, Paris.
§ INRAE, Biologie du Développement et Reproduction, UMR1198 Jouy-en-Josas.
Contact :
o Sophie Griveau (iCLeHS): sophie.griveau@chimieparistech.psl.eu
Phone : +33(0)1 85 78 41 59 / +33(0)6 73 86 94 44
Chimie ParisTech, 11 Rue Pierre et Marie Curie, 75005 Paris