Hierarchically porous membranes for electrochemical ion transfer sensors – HYPERION
Hierarchically porous membranes for electrochemical ion transfer sensors
HYPERION : Mesoporous silica-based electrochemical sensors<br />Available environmental sensors suffer from a lack of sensitivity and selectivity to be able to operate in the environment. HYPERION project aims to build fundamental knowledge allowing the development of innonvative electrochemical sensors.
A need for new environmental sensors
Knowledge about environmental safety is an increasing requirement from stakeholders ranging from the general public, the medical community and environmental agencies. Monitoring programmes of key resources such as water is essential as its contamination by pollutants threatens the health and the well-being of humans. In response to these concerns, environmental policies have been established and regulations have been implemented in most of the industrialised countries. Within the European Union, two essential regulations have been passed in the past decade: the Water Framework Directive (WFD, European Directive 2000/60/EC) and the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH, European Directive 2006/121/EC). The implementation of regulations and directives imposes a great challenge to analytical chemists. Water analysis is a lengthy and complex, multistep, laboratory-based process. Such lengthy process does not favour rapid decision making in the case of pollution events and may result in economic losses and public health issues. There is a need for new analytical tools for environmental monitoring, in particular for alarm systems
HYPERION sensors are based on the transfer of an ionic species between two immiscible phases separated by a hierarchically porous membrane made of a polymer and of mesoporous silica. This kind of sensors combines the sensitivity of voltammetric sensors with the possibility of detecting pollutants, which do not possess redox properties, necessary for classical voltammetric sensors. This project contributed to develop the knowledge necessary for the preparation of such sensors and the investigation of their potential as environmental sensors. A mesoporous silica layer was electrodeposited on a polymeric membrane with a controlled geometry. Characterisation of the fabricated membranes was realised with a large range of physical chemistry techniques
HYPERION project contributed to the elaboration of membranes with a hierarchical porosity based on a macroporous polymeric membrane and a mesoporous silica layer, which was electrogenerated. This double level of porosity –on both microscopic and nanoscopic scale – improve the sensitivity, while the chemical nature of silica offers selectivity. Based on the electrochemical method, the silica thickness is optimised to improve 24-fold the detection of a model ion.
The method developed in HYPERIN has paved the way for innovative electrochemical sensors. Furthermore, new international collaborations have seen the light with groups based in Germany, Australia, Ireland and Poland, allowing new perspectives for the electrogeneration and the investigation of materials at the liquid-liquid interface.
The results of HYPERION have been reported in 6 scientific articles at the time of the project end.
Existing electrochemical sensors for environmental monitoring suffer from limitations in terms of sensitivity and selectivity. Better sensors are needed to respond to the rising societal demand for continuous information on environmental safety. The HYPERION project will investigate the development of functionalised membranes hierarchically porous to form a new class of electrochemical sensors based on ion transfer voltammetry. The sensors will consist of a macroporous polymeric membrane modified electrochemically with a mesoporous silica film. This project will focus on (i) the preparation of hierarchically porous membranes using sol-gel chemistry and micro-fabrication methods, (ii) the understanding of the formation mechanism and (iii) the exploitation of the selectivity properties of the pore dimension and of the surface chemistry for analytical applications. The research developed in this project will combine (i) microscopic features to improve the mass transport and (ii) mesopores with chemical functions to boost both sensibility and selectivity. This project will establish the fundamental knowledge for the development of a novel class of electrochemical sensors.
Project coordination
Grégoire HERZOG (Laboratoire de Chimie Physique et Microbiologie pour l'Environnement)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Partner
LCPME UMR7564 Laboratoire de Chimie Physique et Microbiologie pour l'Environnement
Help of the ANR 126,721 euros
Beginning and duration of the scientific project:
September 2014
- 24 Months
