Massachusetts Institute of Technology

Emitech, Inc

Altair Center, LLC

Other

The State University of New York

Igor A Levitsky

Timothy Manning Swager

Claus G Lugmair

Jinsang Kim

Robert Deans

Jye-Shane Yang

Vance Williams

Yijun Miao

Sergei Krivoshlykov

James Castracane

Bai Xu

William B Euler

Natalya Tokranova

Young-Bin Park

Yi-Jun Miao

Disclosed is a new class of transparent conductive coatings based on conductive grids and percolative pattern therefore.

Transparent conductive coating based on percolative grid

The present invention relates to a class of luminescent and conductive polymer compositions having chromophores, and particularly solid films of these compositions exhibiting increased luminescent lifetimes, quantum yields and amplified emissions. These desirable properties can be provided through polymers having rigid groups designed to prevent polymer reorganization, aggregation or &#x3c0;-stacking upon solidification. These polymers can also display an unusually high stability with respect to solvent and heat exposures. The invention also relates to a sensor and a method for sensing an analyte through the luminescent and conductive properties of these polymers. Analytes can be sensed by activation of a chromophore at a polymer surface. Analytes include aromatics, phosphate ester groups and in particular explosives and chemical warfare agents in a gaseous state. The present invention also relates to devices and methods for amplifying emissions by incorporating a polymer having an energy migration pathway and/or providing the polymer as a block co-polymer or as a multi-layer.

Emissive polymers and devices incorporating these polymers

An optochemical detector for detecting various chemical compounds and comprising a flow cell incorporating the sensory element constructed of an organic-inorganic emissive nanocomposite which luminescence spectral response is specific to exposed target vapors and particulates. The change in the luminescent spectral response is measured during this exposure. The detector is equipped with air-jet sampling system functioning in real-time mode for delivery of vapors and particulates to sensory element.

Devices for optochemical detecting of vapors and particulates using porous photonic crystals infiltrated with sensory emissive organics

A chemical sensor for detecting organic or inorganic target vapors and comprising a silicon member having a silicon surface with semiconductor pores therein, at least one luminescent sensory material entrapped in the semiconductor pores. The luminescent spectral material is exposed to the target vapors, wherein an excitation of the at least one luminescent sensory material results in a luminescent spectral response due to emission interference. The change in the luminescent spectral response is measured during this exposure.

Optochemical sensors for the detection of low pressure vapors based on porous semiconductors and emissive organics

A method of vapor sampling and its delivery to the porous sensory element(s) employed in chemical detectors/sensors for vapor(s) identification and quantification. The sampling and delivery system comprises a flow cell in which a sensory membrane is placed parallel to the flow, while an additional flow normal to the membrane is introduced using the Bernoulli effect. The bi-directional flow of vapors increases the interactions between the sensory material and vapor molecules, and enhances sensitivity.

Amplified sensitivity of porous chemosensors based on bernoulli effect

A method for forming a photovoltaic cell which includes forming a nanostructured layer in a semiconductor material having a plurality of pores opening onto a surface, the plurality of pores having a depth greater than about 1 micron and a diameter between about 5 nanometers and about 1,200 nanometers, and disposing an organic charge-transfer material in the pores of the nanostructured layer. A first electrode is attached to the semiconductor material, and a second electrode is attached to the organic charge-transfer material. The semiconductor material has a thickness between about 5 microns and about 700 microns. Desirably, the nanostructured layer has a porosity of less than the porosity corresponding to the percolation threshold, and the organic charge-transfer material extends at least about 100 nm from the surface of the nanostructured layer. The organic charge-transfer material may partially cover the sides of the pores of the nanostructured layer thereby providing a generally cylindrical cavity therein.

Hybrid solar cells based on nanostructured semiconductors and organic materials

A fluorescence-based method for highly sensitive and selective detection of analyte molecules is proposed. The method employs the energy transfer between two or more fluorescent chromophores in a carefully selected polymer matrix. In one preferred embodiment, signal amplification has been achieved in the fluorescent sensing of dimethyl methylphosphonate (DMMP) using two dyes, 3-aminofluoranthene (AM) and Nile Red (NR), in a hydrogen bond acidic polymer matrix. The selected polymer matrix quenches the fluorescence of both dyes and shifts dye emission and absorption spectra relative to more inert matrices. Upon DMMP sorption, the AM fluorescence shifts to the red at the same time the NR absorption shifts to the blue, resulting in better band overlap and increased energy transfer between chromophores. In another preferred embodiment, the sensitive material is incorporated into an optical fiber system enabling efficient excitation of the dye and collecting the fluorescent signal form the sensitive material on the remote end of the system. The proposed method can be applied to multichromophore luminescence sensor systems incorporating N-chromophores leading to N-fold signal amplification and improved selectivity. The method can be used in all applications where highly sensitive detection of basic gases, such as dimethyl methylphosphonate (DMMP), Sarin, Soman and other chemical warfare agents having basic properties, is required, including environmental monitoring, chemical industry and medicine.

Method of signal amplification in multi-chromophore luminescence sensors

A fluorescence-based method for highly sensitive and selective detection of volatile organic compounds such as vapors of benzene, alcohol, chloroform, dimethyl methylphosphonate (DMMP) that is a simulant of Sarin, Soman and other chemical warfare agents, is proposed. The method employs the effect of strong fluorescence change in thin films of aggregated porphyrins. In one preferred embodiment, the aggregation of porphyrin molecules leads to initial depression of chromophore emission due to self-quenching effect. The binding of analyte molecules to porphyrin sensitive layer forms porphyrin-analyte complexes, which destroy initial aggregate structure and induce the strong fluorescence enhancement. Aggregate-sensing films usually provide higher and faster response than porphyrins isolated in a polymer matrix. That results in strong enhancement of the florescence quantum yield and shift of the fluorescent spectrum in the direction of shorter wavelengths. The method can be used in fluorescence chemical sensors of organic vapors for different applications including environmental monitoring, control of industrial processes and medicine.

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Fall River, MA, United States of America

Igor A Levitsky