The dissertation focuses on the engineering of light-matter interaction using plasmonic nanoparticles and metamaterials to achieve enhanced luminescence and based on which to improve the performance of biosensing and light-emitting technologies. We designed and fabricated a spectrum of nanostructures to exhibit particular dispersion relations capable of controlling the spontaneous emission...
An innovative silver nano-dimple arrays (Ag DAs)-integrated microfluidic device was developed to achieve highly sensitive fluorescence-based nucleic acid detection. The Ag DAs were utilized to produce surface plasmon resonance (SPR) for strong fluorescence enhancement. We systematically investigated the plasmon-enhanced fluorescence by controlling the nanostructure dimension of the Ag DA substrate....
The thesis focuses on the development of a novel printed resistive humidity sensor and integrated flexible electronics for an RFID-enabled humidity sensing platform. We explored a hybrid nanocomposite material for humidity sensing consisting of carbon nanomaterials, conductive polymer and cellulose polymer that undergoes resistance change in response to humidity change....
We demonstrated a low-cost and high-sensitivity DNA detection method using quantum dot-fullerene based molecular beacons (MBs) and magnetic nanoparticles. The MB tethered magnetic nanoparticles can be well dispersed in analytes for efficient DNA capture and concentrated by an external magnetic field for enhanced fluorescence signal detection. The detection requires only...
We demonstrated a sensitive biosensor based on plasmonic metal composite nanostructures. The device can be fabricated and duplicated with ease using a novel nanoprinting technology which allows precise transfer of metal nanostructures without complicated lithography processes. The design featured by its unique material composition and sub-wavelength structures maximizes the exposure...
Unlike other biosensing, electrochemical biosensor has the advantages of robustness, easy miniaturization, excellent detection limits, and capability in handling small analyte volumes. The detection selectivity of the electrochemical biosensors is mainly supported by bioreceptors. However, these receptors always suffer from the performance variation caused by the environment and the thermal-...
Rapid and sensitive detection of stress hormones, such as cortisol and dehydroepiandrosterone (DHEA), can benefit the diagnosis of diseases related to adrenal gland disorders, post-traumatic stress disorders, chronic fatigue syndrome, and more. Stress hormones fluctuate in a circadian rhythm, the highest in the early morning and the lowest at night;...
RNAs play important roles in the central dogma of molecular biology, and are involved in multiple biology processes such as chromatin modification, transcriptional interference and translation initiation. The functions of RNAs, especially non-coding RNAs, are highly related to its secondary structures, therefore computational methods for RNA structure prediction are of...
We report optical modulation of continuous terahertz (THz) wave in the frequency range of 570-600 GHz using photo-induced reconfigurable patterns on a silicon wafer. The patterns were implemented using programmable illumination from a commercially-available digital light processing (DLP) projector. A modulation depth of 20 dB at 585 GHz has been...
Microfluidics is an evolving field that focuses on the manipulation of small fluid volumes. Because of its micron-sized features, it is the basis for many lab-on-chip and point-of-care diagnostic devices. The devices are predominantly molded from polydimethylsiloxane (PDMS); however, production is a multi-hour or multi-day process that typically requires clean...