ENVR 185

Pb²⁺ detection in hybrid nano/microfluidic device utilizing DNAzymes immobilized on gold-coated nanocapillary array membrane

Aigars Piruska, apiruska@nd.edu, Department of Chemical and Biomolecular Engineering, University of Notre Dame du Lac, 311 Cushing Hall, Notre Dame, IN 46556, Yi Lu, Department of Chemistry, University of Illinois, Urbana-Champaign, and Paul W. Bohn, pbohn@nd.edu, Department of Chemical and Biomolecular Engineering, University of Notre Dame, 301 Cushing Hall, Notre Dame, IN 46556.

DNAzymes are appealing alternatives for heavy metal detection in environmental water samples. Selective Pb²⁺ detection has been demonstrated previously with DNAzyme constructs that consist of double-stranded DNA complex with a single RNA base in one of the strands. In the presence of the analyte, the strand is cleaved at the RNA base that results in dehybridization of the DNAzyme complex. Thus optical detection of labeled single-strand DNA fragments is used for Pb²⁺ detection. Previously, immobilization of DNAzyme constructs on gold-coated nanocapillary array membranes (NCAMs) has been shown and characterized in some detail. Current work involves investigating the potential of Pb²⁺ sensing in a hybrid nano/microfluidic device with gold-coated NCAM. The device consists of a NCAM that is sandwiched between two microfluidic channels. The gold-coated NCAM is used as a solid support for DNAzyme immobilization. The high surface-to-volume ratio and small dimensions of nanopores are advantageous for rapid analyte delivery and detection. Electrochemical desorption of DNAzyme constructs is investigated for dosimeter type of operation that could lead to significantly lower detection limits.

Sensors for Detection and Quantification of Contaminants in Drinking Water and the Environment
1:30 PM-5:10 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 235, Oral

Division of Environmental Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008