For WATER Quality Monitoring – 4WATER

The sensing platform will be based on a carbon nanotube field effect transistor that will be used for transduction. We will then develop fonctionnalisation layers that render this sensitive platform selective to the targeted analytes. For the manufacturing of these sensors, inkjet deposition will be used which will require the development of various inks (for nanotubes and fonctionnalisation).
Some of these inks will contain colloidal suspension based on exfoliated mineral materials. We will therefore study such suspension from a structural point of view.
Finally, we will develop acquisition mother board to enable the first standalone prototype.

* Various materials have been exfoliated and the physico-chemical properties investigated (together with their mixing with polymers).
* Various CNTs inks have been formulated for the making of CNT-FET
* New CNT-FETs have been produced and functionalized.
* Sensor responses to pµH and other analytes have been measured (results submitted for publication).
* 2 PhD thesis will be defended in december 2021.

* Inorganic nanosheet lamellar phase demonstrated (article in PNAS);
* The addition of polymers to nanosheet suspensions can have opposite results;
* Theoretical work has been performed to explain such behavior;
* Formulation for the deposition of fonctionnalisation layer have been produced (patent pending);
* First sensors have been produced that showed good response to pH.

BREVET:
1) Method for protecting air-sensitive or evaporation-sensitive objects, WO/2021/089957: patentscope.wipo.int/search/fr/detail.jsf


PUBLICATIONS:
1) « Isotropic, nematic, and lamellar phases in colloidal suspensions of nanosheets. » P. Davidson, C. Penisson, C. Doru, J.C.P. Gabriel, Proc. National. Acad. Sc. 201802692 (2018). doi.org/10.1073/pnas.1802692115

2) « Methods for dispersing carbon nanotubes for nanotechnology applications: liquid nanocrystals, suspensions, polyelectrolytes, colloids and organization control. » S Manzetti, JCP Gabriel, International Nano Letters 9 (1), 31-49 (2019) doi.org/10.1007/s40089-018-0260-4

3) « Destabilization of the Nematic Phase of Clay Nanosheet Suspensions by Polymer Adsorption » Karin El Rifaii, Henricus H. Wensink, Thomas Bizien, Jean-Christophe P. Gabriel, Laurent Michot, Patrick Davidson, Langmuir 36(42) 12563–12571 (2020), doi.org/10.1021/acs.langmuir.0c02084

4) « Fine tuning of the structural colors of photonic nanosheet suspensions by polymer doping » Karin El Rifaii, Henricus H. Wensink, Claire Goldmann, Laurent Michot, Jean-Christophe P. Gabriel, Patrick Davidson, Soft Matter 17(41) 9280-9292 (2021). doi.org/10.1039/d1sm00907a

The water crisis is the #1 global risk based on impact to society as announced by the World Economic Forum in January 2015 [1]. Indeed, groundwater is a scarce resource as it only account for 0.3% of the Earth's total freshwater reserves. And already, 663 million people - 1 in 10 - lack access to safe water and 2.4 billion people - 1 in 3 - lack access to adequate sanitation (including 1/3 of all schools)[2,3] which has been shown to strongly impact local water quality and population’s health [4] Even when safe water is accessible, there can be great variability in its composition depending on many environmental and human factors [5], which can sporadically render it unsafe. Despite this, little is known of this variabilities and interplays because no global and permanent monitoring of these freshwater resources. The reason for this are explained in the proposal and a new low cost, multi-analyte water quality monitoring solution is proposed.
1. World Economic Forum. (2015). Global Risks 2015 Report.
2. World Health Organization and UNICEF Joint Monitoring Programme (JMP). (2015) Progress on Drinking Water and Sanitation, 2015 Update and MDG Assessment.
3. United States Census Bureau Estimates. (2015). United States and World Population Clock.
4. Contribution of Water Pollution From Inadequate Sanitation and Housing Quality to Diarrheal Disease in Low-Cost Housing Settlements of Cape Town, South Africa. Thashlin Govender, Jo M. Barnes, Clarissa H. Pieper, Am J Public Health. 2011 July; 101(7): e4–e9.
5. Spatial and Seasonal Variability in the Water Quality Characteristics of an Ephemeral Wetland. Chad J. Boeckman and Joseph R. Bidwell Proc. Okla. Acad. Sci. 87: pp 45-54 (2007)