Apparatus and methods for optical time-of-flight discrimination in combinatorial library analysis

Abstract

Our recently developed method for combinatorial synthesis leads efficiently to linear arrays, where the location of a compound in the array encodes its complete synthetic history. Such arrays prepared using an optical fiber as a linear support can be probed with a fiber-guided pulse, allowing evanescent interaction with fluorescent probe molecules at the core-cladding interface. Optical time-of-flight distinction among output signals of fluorescent regions distributed along the fiber is carried out, allowing for the measurement of the location of the emitting fluorescent probes. A unique two-fiber, double-evanescent process overcomes limitations in spatial discrimination, due to fluorescence decay times in comparison to the speed of light. Investigation of an array of 102 fluorescent regions is described, with discussion of its features and limitations.

Crossed Optical Fiber Sensor Arrays for High-Spatial-Resolution Sensing: Application to Dissolved Oxygen Concentration Measurements

“…The second fiber provides the time delay necessary to temporally resolve the signals originating at the sensor regions as seen in Figure 1 (for details see [36,37]). This allows for an increased spatial resolution in multisensor arrays, as we demonstrated with an array of 100 crossed fiber junctions in a space of 6 cm × 6 cm [38]. This work is part of our effort to develop sensing elements (i.e., individual sensor junctions) for this sensor-array architecture; the long-term goal is to incorporate various sensing elements for different sensing tasks into this architecture.…”

An Optical Fiber-Based Sensor Array for the Monitoring of Zinc and Copper Ions in Aqueous Environments

“…While some single-metal sensors were developed in the past [ 8 – 10 ], multi-analyte optical fiber sensors have not been extensively investigated. Our crossed-fiber design allows for fabrication of sensor arrays capable of analyzing aqueous environments for metal ions (here copper and zinc) and for spatially resolved readout of these arrays with optical time of flight spectroscopy (OTOFS) [ 11 ].…”

Characterization of time-resolved fluorescence response measurements for distributed optical-fiber sensing

“…Despite the number of potentially important applications, relatively few practical distributed chemical sensing systems based on evanescent field interac-tions have been reported [6][7][8][9][10]. This is primarily due to the difficulty of protecting the optical-fiber sensor while allowing sufficiently sensitive interaction between the target chemical species and the guided light in the fiber core.…”