ORC Seminar Series
"PHOTONIC NANOBIOSENSORS FOR LAB-ON-A-CHIP APPLICATIONS"
Speaker: Professor Laura Lechuga
Nanobiosensors and Molecular Nanobiophysics Group, Research Center on Nanoscience and Nanotechnolgy
Date: Wednesday 22nd October 2008
Venue: Lecture Theatre B, Building 46
Nowadays most of the tests for diseases detection are based on time-consuming, expensive and sophisticated techniques. Photonic nanobiosensors can offer early diagnostic tools of better sensitivity, specificity and reliability which could improve the effectiveness of in vivo and in-vitro diagnostics. They can allow measurements in real-time with very low volumes (nl) of samples and are able to identify and quantify protein biomarkers and single DNA mutations at extremely low concentrations, without using labels. Our last developments in photonic biosensors will be shown, mainly related to the development of portable and highly sensitive photonic lab-on-a-chip platforms. Two types of photonic biosensors have been implemented:
(i) Ultrasensitive and miniaturised photonic silicon sensor based on integrated Mach-Zehnder interferometers of micro/nanodimensions which are monolithically integrated with a 3D-polymeric microfluidic network. The sensor has been applied to the real-time and label-free detection of DNA single point mutations at the gene BRCA-1, related to the predisposition in women to develop an inherited breast cancer. The MZI sensor has successfully discriminated between normal and mutant sequences and shows a limit of detection in the pM range for fully hybridisation and in the nM range for single mutations detection.
(ii) Nanomechanical biosensors based on waveguided microcantilevers which we have introduced as a new type of read-out technique. The microcantilevers are optical waveguides operated in visible range. The principle of operation is based on the sensitivity of energy transfer between two butt-coupled waveguides to their misalignment with respect to each other. This new device has shown the same performance for biosensing than conventional microcantilever sensors and offers an interesting approach for further integration in lab-on-a-chip microsystems
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