Award Abstract #0304523
NIRT: Developing a Nanoscale Sensing Device for Measuring the Supply of Iron to Phytoplankton in Marine Systems

NSF Org:	CBET Division of Chemical, Bioengineering, Environmental, and Transport Systems
Initial Amendment Date:	August 14, 2003
Latest Amendment Date:	August 14, 2003
Award Number:	0304523
Award Instrument:	Standard Grant
Program Manager:	Clark C. K. Liu CBET Division of Chemical, Bioengineering, Environmental, and Transport Systems ENG Directorate for Engineering
Start Date:	August 15, 2003
Expires:	July 31, 2007 (Estimated)
Awarded Amount to Date:	$903840
Investigator(s):	Mark Wells mlwells@maine.edu (Principal Investigator) D. Whitney King (Co-Principal Investigator) Carl Tripp (Co-Principal Investigator) Karen Orcutt (Co-Principal Investigator)
Sponsor:	University of Maine 5717 Corbett Hall ORONO, ME 04469 207/581-1484
NSF Program(s):	NANOSCALE: INTRDISCPL RESRCH T, ENVIRONMENTAL ENGINEERING
Field Application(s):	0313040 Water Pollution, 0316000 Trace Contaminants
Program Reference Code(s):	EGCH, 9187, 9150, 4444, 1674
Program Element Code(s):	1674, 1440

ABSTRACT

0304523

Wells

Intellectual Merit of the Proposed Activity:

This proposal was received in response to NSE NSF-02-148.

There is increasing evidence that Fe has a singularly unique role in marine ecosystems, both regulating total phytoplankton production in high nitrate, low chlorophyll regions of the world, and influencing the predominant composition of the phytoplankton assemblages found in others. It is remarkable then that there is no agreement about how to define biologically available Fe, in contrast to the macronutrients nitrogen, phosphorous or silicon. Current attempts to attain predictive insights to how ocean ecosystems will influence the magnitude of climate change are blocked in large part by this question, along with an extreme shortage of data on Fe distributions in the oceans. There is recent evidence that Fe availability can be regulated in bulk seawater incubations by small additions of the fungal siderophore desferrioximine B (DFB). The Fe-DFB complex is not readily available to eukaryotic phytoplankton, so that if the quantity of Fe complexed by DFB were measured and calibrated to Fe uptake by phytoplankton it could yield a novel first order measure of Fe availability. Building from our current research we have developed liposomes that specifically acquire DFB-bound Fe from solution. These devices, 100 nm in diameter, open the way to applying nanotechnology to create a new breed of Fe biosensors in marine waters.

The project goals are to 1) optimize these nanodevices by improving their physical robustness, identifying the size/functionality relationship, and examining the efficacy of other DFB-Fe transporter molecules, 2) develop self-reporting capabilities for quantifying Fe uptake by these nanodevices, and 3) to calibrate the capture of Fe by these nanodevices to the Fe uptake by various phytoplankton species. The anticipated final product will be a calibrated nanoscale biosensor for laboratory-scale use that could then be adapted for deploying on remote vehicles.

Broader Impacts Resulting from the Proposed Activity: The two institutions involved in this project (U. Maine and Colby College) have a strong track record for involving undergraduate and graduate students in cutting edge research in marine science and chemistry, and this project will continue this process.

PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH

C. Jiang, A. Gamarnik and C. P. Tripp.. "Tripp Identification of Lipid Aggregate Structures on TiO2 Surface Using Headgroup IR Bands," J. Phys. Chem., v.109, 2005, p. 4539.

C. Jiang, H. Li and C. P. Tripp.. "An infrared method for in situ studies of polymer/surfactant adsorption on silica powders from aqueous solution," Applied Spectroscopy, v.57, 2003, p. 1419.

K.M. Orcutt and M. L. Wells. "A liposome based nanodevice for sequestering siderophore bound Iron," Journal of Membrane Science, v.288, 2007, p. 247.

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