Year: 2012
Jiří Homola
Cooperation: Karl-Franzens University, Graz, and the Institute of Hematology and Blood Transfusion, Prague
Optical biosensors based on surface plasmons (SPs) represent an emerging technology that enables rapid and sensitive detection of biological analytes with potential applications in medical diagnostics, environmental monitoring, food safety and security. With the advent of nanoscience and nanotechnology, miniaturization of plasmonic sensors (even down to a single nanoparticle) has become an important goal. We have investigated various types of plasmonic nanostructures and explored their potential for the development of high-performance plasmonic sensors. In collaboration with the Karl-Franzens University, Graz, we investigated detection capabilities of sensors based on SPs on an array of gold nanorods and SPs on a macroscopic gold film [1]. We demonstrated that although the nanorod-based sensor requires a significantly lower number of biomolecular interactions to take place to produce a sensor output, the resulting analytical performance of the two sensors, expressed in terms of the limit of detection, is approximately the same [1]. We have also explored the effects of mass transfer and molecular interaction properties [12]. In addition, we demonstrated plasmonic biosensors for the detection of carcinoembryonic antigen (CEA; elevated levels of CEA indicate gastrointestinal, breast, or lung carcinoma) [13] and vascular endothelial growth factor receptor (implicated in myelodysplastic syndromes and acute myeloid leukemia) [14]. Combining a sensor based on spectroscopy of surface plasmons with functionalized gold nanoparticles enhancing the sensor response, CEA was detected at levels as low as 100 pg/mL – an order of magnitude below the physiological levels of CEA for healthy individuals [13].