整合零模波導及二維過渡金屬二硫族化物奈米發射器應用於單分子即時感測(1/2)

Virus caused diseases have cost tremendous loss of human lives and globaleconomies. Considering such a threat to human being persists, major researchresources are delivered to the development of vaccines, rapid test modalities andprotection equipments, regardless countries. To be capable of probing singlemolecules in real time at biological relevant concentrations, typically atmicromolars, is still challenging. In this project, the integration of zero-modewaveguides (ZMWs) with transition metal dichalcogenides (TMDs) nanoemitterswill be performed to achieve this goal. The great advantages of using TMDs aretheir high second-order optical nonlinearity and valley-specific transitions whichaltogether provides good isolation from unwanted backgrounds. According tosimulations, combining ZMWs and plasmonic nanoantennas may yield anexcitation volume below zeptoliters and a fluorescence lifetime down to ~100femtoseconds. This will benefit to the study of ultrafast biomolecular processes.Finite-difference time-domain (FDTD) method will be used to design the ZMWsaiming at achieving the smallest possible excitation volume and the shortestpossible fluorescence decay time. In terms of fabrication, standard focused ionbeam (FIB) lithography and flip-chip bonding by plasmon assisted laser weldingtechnique will be employed. To assess device performance, standard dyes withknown fluorescence decay characteristics will be used wherein time-correlatedsingle-photon counting (TCSPC) and fluorescence correlation spectroscopy(FCS) data will be analyzed. As a proof of real-time sensing, plasmonic nanostars(NS) will be utilized as a fluorescence intensifier, and as a polarization reporterdue to multi-branched structures. The formation of protein corona (NS-proteincomplexes) is selected as model system since this mimicks the protein-ligandrecognition process in biology. The major concern here will focus on theinterplays between chirality. To cope with real-time detection, a Stokespolarimetry basing on conical refraction will be employed for measuring thepolarization states of the emission from ZMWs. The corresponding spectralinformation will be analyzed by the nanocolorimetry we previously established