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Title: Novel detection strategies using SERS
Author: Cecchini, Michael Peter
ISNI:       0000 0004 2737 7393
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2013
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The use of surface-enhanced Raman spectroscopy (SERS) as an analytical tool has gained increased interest in recent years due to its greater sensitivity and “fingerprinting” ability when compared to other spectroscopic techniques. This thesis discusses approaches used to detect aggregated and single metallic nanoparticles in a high throughput fashion using SERRS. This was accomplished by building a sensitive optical detection platform with high temporal resolution detectors. Initially, nanoparticle aggregates compartmentalized within microdroplets were detected. Each microdroplet can be considered an individual microreactor. Microdroplet flow rate was changed to characterize the effect on microdroplet throughput. Multiple full spectra acquisitions were taken within each microdroplet which was used to compare the different aggregate geometries within each droplet. In addition to segmented flow, single particles in a continuous flow environment are also detected and characterized. A flow based system significantly increases nanoparticle throughput through the probe volume reducing acquisition time. Using correlation spectroscopy, the size of the nanoparticle can be determined and the effect of flow rate on the nanoparticle flow time can be seen. As another detection strategy, single metallic nanoparticles are also detected optically as they translocate through a solid state nanopore. The high electric field generated at the nanopore electrophoretically drives the charged nanoparticles through the nanopore. The nanopore confines the particles to a single channel ensuring single particle detection. Besides the vibrational information that SERS is able to extract, coupling metallic nanoparticles with metallic nanoparticles creates an additional electromagnetic enhancement with increases the SERS signal.
Supervisor: Edel, Joshua ; McComb, David ; Albrecht, Tim Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available