BioMatNet Item: QLK3-2000-00481 - Sensor arrays for environmental, generic and routine detection of pesticides

[BioMatNet Database - FP5 Quality of Life Programme]

QLK3-2000-00481
Sensor arrays for environmental, generic and routine detection of pesticides

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Biotechnology : Fine Chemicals : Quality of Life - 3. The Cell Factory

Type of Project	Research project
Contract No	QLK3-2000-00481
Total Cost
EC Contribution	1,227,438
Start Date	01-12-2000
Duration	36 Months

Abstract

The SAFEGUARD project is focused towards developing a range of biosensors, dedicated instrumentation and associated software for the detection, quantification and monitoring of pollution events that are related to environmental pesticide loadings.

The biosensors to be developed within this project will mainly be based on the cholinesterases, which are the targets of many pesticides. A range of differentially selective enzymes will be exploited together with a number of recombinant insect cholinesterases having considerably greater sensitivity to pesticide concentration than previously used.

Dedicated electronic address systems, control systems and data processing will be developed, together with specialised software for data processing and de-convolution of sensor responses. A laboratory prototype instrument will finally be realised, via the incorporation of pesticide specific sensor arrays, specialised de-convolution systems and dedicated electronics developed within the project.

Objectives

The objectives of the project are:

To produce modified, bioengineered, stabilised recombinant cholinesterase enzymes, differentially selective to a range of pesticides and to screen ATPases and phosphatases for pesticide sensitivity.
To produce a range of transducer types and micro-electrode arrays for the production of pesticide sensors.
To integrate novel, patented stabilisation technology to improve sensor sensitivity and to create sensor arrays.
To create new interfacial electrochemical surfaces using novel immobilisation technologies.
To design dedicated electronics and software for system control, with data processing capabilities and to investigate new electronic address systems.
To produce laboratory prototype instrumentation.
To evaluate the sensor arrays produced for use in pesticide monitoring.

Activitives

This project is aimed at section 3.2.2 of Key Action 3, which states, 'Aspects for consideration: bioassays and biosensors for fast and efficient warning of pollution incidents and to assay the level of pollution. These systems will also serve for monitoring where in situ remediation is carried out'. The creation of sensor arrays to rapidly detect, quantify and monitor pollution events that are related to environmental pesticide loadings, centrally address the stated objective of this specific action point. Already detection limits of 10 (-10) M have been achieved by one partner of the project, with a time of detection in the order of minutes in untreated water samples. The new biosensors to be developed originate mainly from cholinesterases, which are the targets of many pesticides. Recombinant insect cholinesterases having 50-100 times more sensitivity to pesticide concentration will be incorporated in the project. Specific bio-engineering of the structure will give a range of differentially selective enzymes, with specific binding motifs to allow oriented immobilisation to occur.

Also pyrethroids will be screened for inhibition of other enzymes. Novel transducers, including metal on silicon doped carbon and porous carbon will be manufactured. Sensors will be fabricated in a variety of ways, with an interative 3 phase process involving surface modification and immobilisation, characterisation and optimisation of the fabrication process. Patented stabilisation systems that have a two fold effect of enzyme activity stabilisation and molecular micro-environment orientation, leading to enhanced electrochemistry and thus lower detection levels will be included in these phases. Dedicated electronic address systems, control systems and data processing will form part of the work, together with specialised software for data processing and de-convolution of sensor responses. Finally, drawing on the results from several workpackages, the production of laboratory prototype instruments will be realised, incorporating pesticide specific sensor arrays, dedicated de-convolution systems and dedicated electronics. Evaluation of the sensor arrays and comparison of standard measuring techniques will round off the project.

Deliverables

A list of deliverables for the project are detailed below together with approximate timings (in months) from the commencement of the project:

Supply of first commercial and recombinant enzymes (month 2).
Supply of first bioengineered cholinesterases and mutants with ligand tags (month 12).
Supply of mutant enzymes for thiophosphate detection (month 24).
Characterisation of wild type and mutant enzymes (month 36).
Stocks of screen printed carbon and CoPt loaded carbon transducers (month 2).
Stocks of metal (gold, platinum and nickle) on silicon transducers (month 6).
Porous carbon transducers (months 12-24).
Microelectrode arrays (months 18-36).
Sensors based on carbon and carbon CoPt and metal on silicon transducers (months 12-34).
Sensors produced by supramolecular layering (months 18-36).
Entrapped enzyme micro-electrode arrays (months 24-36).
Immobilisation procedures for sensor production (month 36).
A range of sensor types with the suitable analytical and stability characteristics (months 12-36).
Characterisation datasheets for each sensor type (month 36).
Optimised protocols for prototype sensor fabrication (month 36).
Dedicated electronics for system control and data collection (months 18-36).
Specialised electronics for sensor characterisation (month 18).
Dedicated software for control of instrumentation (months 12-24).
Dedicated software for signal processing.
Working prototype sensor system.

Contacts

Coordinator

S. HIGSON / Manchester Materials Science Centre Bio-electrochemistry Group (BEG) / UNITED KINGDOM

Participant