Nanoplasmonic Biosensing - Exploring Unique Possibilities
Doktorsavhandling, 2010

Bioanalytical sensors are indispensible tools in medical diagnostics and drug discovery as well as for life science research, environmental monitoring and food safety. In essence, they are used to detect and determine the concentrations of specific biomolecules in complex mixtures. In this work, challenges of current technologies are addressed using biosensors based on the peculiar optical properties of metal nanostructures and in particular, the sensitivity of these nanoplasmonic properties to changes in the refractive index of the surrounding environment. The main focus has been to explore unique possibilities provided by nanoplasmonic sensors. This includes utilizing the tight confinement of the sensitivity to the surface to investigate structural biomolecular changes. Nanoplasmonic structural sensing was further investigated using combined nanoplasmonic and quartz crystal microbalance (QCM) measurements. This was conducted using a thin gold film perforated with nanoholes, which served as both the nanoplasmonic sensor and one of the electrodes of the QCM sensor. Even with the most sensitive surface-based sensor, molecules can only be detected if they reach the surface and bind. In fact, the transport of molecules to the sensor surface can be a limiting factor for the performance of a biosensor. Ways of improving mass transport were investigated by (i) flow-through sensing using nanoplasmonic pores and (ii) directed binding to high-sensitivity nanoscale regions using materials-specific surface modifications. Both concepts were shown to enable a reduction in the sensor response time of more than one order of magnitude compared with conventional diffusion-limited binding. Finally, one reason for the potential of nanoplasmonic sensors stems from their competitive performance combined with relatively simple instrumentation and the possibility for scalable and low-cost fabrication. Steps towards a portable nanoplasmonic sensor device, for example to be used for medical diagnostics at point-of-care, were taken by integrating the opto-electrical conversion directly on the sensor chip. This was achieved by designing the nanoplasmonic sensor structure on an array of photoactive diodes. By simple means, specific protein binding could be detected in a label-free and real-time format through changes in the photocurrent output.

biosensor

nanoholes

nanopores

nanofabrication

localized surface plasmon resonance

quartz crystal microbalance

nanoplasmonics

structural sensing

artificial cell membrane

Kollektorn, Kemivägen 9, Göteborg, Chalmers tekniska högskola
Opponent: Prof. Harold Craighead, School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA

Författare

Magnus Jonsson

Chalmers, Teknisk fysik, Biologisk fysik

Locally Functionalized Short-Range Ordered Nanoplasmonic Pores for Bioanalytical Sensing

Analytical Chemistry,; Vol. 82(2010)p. 2087-2094

Artikel i vetenskaplig tidskrift

Improving the Limit of Detection of Nanoscale Sensors by Directed Binding to High-Sensitivity Areas

ACS Nano,; Vol. 4(2010)p. 2167-2177

Artikel i vetenskaplig tidskrift

Nanoplasmonic biosensing with on-chip electrical detection

Biosensors and Bioelectronics,; Vol. 26(2010)p. 1131-1136

Paper i proceeding

Ämneskategorier

Telekommunikation

Atom- och molekylfysik och optik

Biofysik

Annan industriell bioteknik

Den kondenserade materiens fysik

ISBN

978-91-7385-463-4

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 3144

Kollektorn, Kemivägen 9, Göteborg, Chalmers tekniska högskola

Opponent: Prof. Harold Craighead, School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA