Objectives

(1) to improve and validate analytical methods for gaseous Hg speciation needed in atmospheric measurements (ESR10) and (2) to develop in-situ biosensors for the determination of the bioavailable fraction of Hg in the aquatic environment (ESR11) and (3) to test new and validated methodologies for analysing the atmosphere and water during field campaigns.

Description of Work

Task 4.1. To secure comparability of atmospheric measurements traceable calibration methodology (with stated uncertainties) for the most important oxidized Hg species will be applied for low level atmospheric measurements under contrasting conditions during lab and field campaigns. This will be done via a traceable Hg(0) standard developed by VSL where the ESR 10 will be seconded twice.  Conventional calibration will be tested against newly developed plasma source of Hg(II) followed by mass spectrometry detector. Improved conventional measurement methods based on selective sorbent trapping, denuders and impingers developed and tested by MercOx project coordinated by PC (www.mercox.si) will be applied in WP1 and 2. Also, high accuracy bulk and species-specific [e.g. Hg(0) and Hg(II)] isotope ratio measurements by MC-CP-MDS will be evaluated for origin discrimination during secondment at the JSI. The methods validated for atmospheric measurements will be tested using new and conventional methods for Hg speciation measurement in the atmosphere during field measurements campaigns organized by WP1 and 2.

Task 4.2. ESR11 will develop a highly specific, robust and sensitive MMHg biosensor. In phase I, the ESR11 will develop approaches of using information stored in DNA. By the D/RNA manipulation ESR11 will prepare biomolecules, either DNA, RNA or proteins, that specifically bind to MMHg. This work will be implemented together with the JSI that will host ESR11 during their secondments. Two approaches will be used (i) based on directed evolution applying synthetic biology circuits to increasing specificity of binding of proteins and (ii) by using a selection process (SELEX) of RNA and DNA molecules resulting in aptamers with high MMHg affinity constants and specificity. The final structure of the biosensor will depend on the nature of the biological components, on the nature of the inverter and on the corresponding detection methods. In phase II, ESR11 will validate the developed biosensor by making parallel measurements using conventional analytical methods on different types of environmental samples obtained from AMU, IFREMER, and SU.

Expected Results

ESR10

Validated calibration sources for Hg(0) and Hg(II) for low level gaseous Hg measurements. Validated and tested protocols applied at observation stations and cruises (2 papers).

ESR11

Synthetic biology circuit of directed evolution for proteins of high MMHg specificity. DNA and RNA biomolecules with high MMHg binding affinities obtained and characterised. Mesoporous material with immobilised biomolecules prepared and the prototype biosensor for MMHg detection in seawater validated. Biosensor onsite testing (2 papers).

Deliverables

Del. Deliverable Title – Science deliverables WP Lead Type Diss. Due
D4.1 ESR10: 2 papers on (i) validated calibration sources for Hg(0) and Hg(II) for low level gaseous Hg measurements; (ii) developed and field validated methods for Hg speciation in the atmosphere. 4, 1 PSA PDE PU M24, 46
D4.2 ESR11: 2 papers: (i) evaluation and testing of proteins with high MMHg specificity; (ii) biosensor for MMHg detection in seawater. 4, 2 IOS PDE PU M24, 46
D15 PhD diplomas for 15 ESRs 1-6 All PDE PU M48

Milestones

No Title WP(s) Lead Benef. Due Date Means of Verification
1 Validated and calibrated methodology for GOM and GEM developed by ESR10 1, 4 PSA M10

Secondments at PSA, VSL, JSI

Completed for ESRs1 and 2

3 Specific biomolecules for MMHg sensing identified 4, 3 IOS M18 Report  on testing and cross-validation in collaboration with JSI
7 Traceable calibration sources for Hg(0) and Hg(II) 4, 1 PSA M24 Report on validation and  calibration
8 MMHg selective and coupled biomolecules with nanomaterials tested (lab and field) 4, 3 IOS M24 Material tested and cross-validated in collaboration with JSI
12 New cruises and data on marine Hg speciation 2, 5 AMU M36 Cruises completed, data verified
13 New data on coastal Hg speciation 2, 5 UPPA M30 Measurements completed and validated
19 Biosensor developed 4 IOS M40 Biosensor validated and tested
24 PhD thesis submitted 1-6 all M48 PhD thesis approved by (co)supervisors