DNAzyme and aptamer based biosensors for on-site real time monitoring

INOR 92

Debapriya Mazumdar, dmazumda@uiuc.edu, Juewen Liu, Mehmet Yigit, Jung Heon Lee, jhlee1@uiuc.edu, and Yi Lu. Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Goodwin Ave., Urbana, IL 61801
Sensors for on-site and real-time monitoring of analytes is an important area of research for environmental, clinical and defense applications. We use a combinatorial biology method called in vitro Selection to obtain DNAzymes (DNA with enzymatic activities) and aptamers (nucleic acids that bind an analyte) that can bind a broad range of analytes strongly and specifically. By labeling DNAzymes and aptamers with gold nanoparticles, we have developed colorimetric sensors for metal ions (such as lead, uranyl, potassium), organic and biomolecules (such as cocaine and adenosine). Practical applications such as the detection of Pb(II) in leaded paint has been demonstrated using the colorimetric biosensor below the federal threshold of 1 mg/cm2. To further improve the ease of use, we are exploring DNAzyme/aptamer based lateral flow devices, similar to the home pregnancy test kits. A sensitive “dip-stick” type test has been developed for detection of adenosine and cocaine in serum. Recent progress in this area will be discussed.