Patents by Inventor Michael H. Stewart

Michael H. Stewart has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20240118204
    Abstract: A semiconducting nanocrystal (quantum dot or QD) and ferric dithiocarbamate complex (QD-Fe(DTC)3) operate as a sensing system to detect nitric oxide (NO) in ambient conditions using fluorescence resonance energy transfer (FRET). The sensing system comprises two components: (1) an energy donor in the form of a dihydrolipoic acid (DHLA)-coated QD with strong fluorescence emission, and (2) an energy acceptor in the form of a ferric ion-dithiocarbamate complex (Fe(DTC)3) that binds onto the QD surface via carboxylate coordination. The ferric ion in the QD-Fe(DTC)3 complex acts a strong energy acceptor, resulting in weak fluorescence (FL) emission (“turn-off”) of the QD when excited using 405 nm light. In the presence of NO, ferric ion (3+) reduces to ferrous (2+), with decreased ability to accept energy from the QD, in turn appearing as increased FL emission from the QD (“turn-on”) as a sensing signal.
    Type: Application
    Filed: September 29, 2023
    Publication date: April 11, 2024
    Inventors: Okhil K. Nag, Michael H. Stewart, Bethany Almeida, James Delehanty
  • Patent number: 11932802
    Abstract: Various shaped abrasive particles are disclosed. Each shaped abrasive particle includes a body having at least one major surface and a side surface extending from the major surface.
    Type: Grant
    Filed: December 2, 2022
    Date of Patent: March 19, 2024
    Assignee: SAINT-GOBAIN CERAMICS & PLASTICS, INC.
    Inventors: Todd M. Cotter, Francois Wagner, Rene G. Demers, Richard J. Klok, Alexandra Marazano, Adam D. Lior, James A. Salvatore, Sujatha K. Iyengar, David F Louapre, Sidath S. Wijesooriya, Ronald Christopher Motta, Gary A. Guertin, Michael D. Kavanaugh, Doruk O. Yener, Jennifer H. Czerepinski, Jun Jia, Frederic Josseaux, Ralph Bauer, Frank J. Csillag, Yang Zhong, James P. Stewart, Mark P. Dombrowski, Sandhya Jayaraman Rukmani, Amandine Martin, Stephen E. Fox, Nilanjan Sarangi, Dean S. Matsumoto
  • Publication number: 20240060118
    Abstract: A FRET based reporter system utilizing the fluorescent semiconductor quantum dots (QDs) and restriction enzymes expressed in cell-free system has the potential to detect multiple analytes in single reaction.
    Type: Application
    Filed: May 30, 2023
    Publication date: February 22, 2024
    Inventors: Scott A. Walper, Igor L. Medintz, Divita Mathur, Sebastian A. Diaz, Meghna Thakur, Kimihiro Susumu, Michael H. Stewart
  • Patent number: 11795483
    Abstract: A nanoplatelet serves as a substrate for immobilizing enzymes involved in consecutive reactions as a cascade. This results in a significant increase in the rate of catalysis as well as final product yield compared to non-immobilized enzymes or enzymes immobilized to quantum dots.
    Type: Grant
    Filed: June 11, 2019
    Date of Patent: October 24, 2023
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Igor L. Medintz, Joyce Breger, Scott Walper, Michael H. Stewart
  • Patent number: 11732186
    Abstract: A process for synthesizing Cu2-xS/PbS core/shell nanocrystals. Pb-oleate is mixed with 1-octadecene and heated to 60° C. Cu2-xS core solution and bis(trimethylsilyl)sulfide stock solution are added and the mixture is stirred at 60° C. for 6 minutes to form the PbS shell around the Cu2-xS nanocrystal cores. The flask is cooled and acetonitrile and toluene is added and the mixture is centrifuged to precipitate and remove the Cu2-xS/PbS core/shell nanocrystals from the reaction mixture. The reaction also produces homogeneously nucleated PbS nanocrystals, which are removed from the Cu2-xS/PbS core/shell reaction mixture via size-selective precipitation. By tailoring the amounts of Pb-oleate and bis(trimethylsilyl)sulfide stock solution in the reaction vessel, while maintaining their molar ratio of 1.5:1 and the number of Cu2-xS cores in the reaction, Cu2-xS/PbS core/shell nanocrystals having a predetermined shell thickness of PbS, and thus a predetermined level of chemical stability, can be obtained.
    Type: Grant
    Filed: April 23, 2021
    Date of Patent: August 22, 2023
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Janice E. Boercker, Sarah F. Brittman, Joseph G. Tischler, Patrick Y. Yee, Chase T. Ellis, Paul D. Cunningham, Rhonda M. Stroud, Michael H. Stewart, Steven C. Erwin
  • Publication number: 20230091507
    Abstract: A quantum dot (QD)-rhodopsin bioconjugate system uses Förster resonance energy transfer (FRET)-mediated induction of cellular membrane depolarization via optical activation of ion channel proteins channelrhodopsin (ChR).
    Type: Application
    Filed: September 16, 2022
    Publication date: March 23, 2023
    Inventors: Okhil K. Nag, Megan E. Muroski, Michael H. Stewart, Alexander Efros, Scott Walper, James Delehanty, Eunkeu Oh
  • Publication number: 20220228061
    Abstract: This disclosure concerns a method of making a ligand for Quantum Dot functionalization, a method of making a functionalized Quantum Dot (QD) with a ligand, and a method of making a transparent luminescent quantum dot thiol-yne nanocomposite with tailorable optical, thermal, and mechanical properties. The prepolymer solution and functionalized Quantum Dot can be used in additive manufacturing.
    Type: Application
    Filed: April 5, 2022
    Publication date: July 21, 2022
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Darryl A. Boyd, Michael H. Stewart, Kimihiro Susumu, Eunkeu Oh, James P. Wissman
  • Patent number: 11287430
    Abstract: A construct for detecting cellular membrane potential includes a nanoparticle operable as an electron donor; a modular peptide attached to the nanoparticle, the peptide comprising a nanoparticle association domain, a motif configured to mediate peptide insertion into the plasma membrane, and at least one attachment point for an electron acceptor positioned at a controlled distance from the nanoparticle; and an electron acceptor. The nanoparticle can be a quantum dot and the electron acceptor can be C60 fullerene. Emission correlates with cellular membrane potential.
    Type: Grant
    Filed: June 8, 2020
    Date of Patent: March 29, 2022
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: James B. Delehanty, Michael H. Stewart, Okhil Nag, Jeffrey R. Deschamps, Kimihiro Susumu, Eunkeu Oh, Lauren D. Field, Alexander L. Efros, Alan L. Huston, Igor L. Medintz, Philip E. Dawson
  • Patent number: 11180696
    Abstract: This disclosure concerns a method of making a ligand for Quantum Dot functionalization, a method of making a functionalized Quantum Dot (QD) with a ligand, and a method of making a transparent luminescent quantum dot thiol-yne nanocomposite with tailorable optical, thermal, and mechanical properties. The prepolymer solution and functionalized Quantum Dot can be used in additive manufacturing.
    Type: Grant
    Filed: October 5, 2018
    Date of Patent: November 23, 2021
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Darryl A. Boyd, Michael H. Stewart, Kimihiro Susumu, Eunkeu Oh, James P. Wissman
  • Publication number: 20210332291
    Abstract: A process for synthesizing Cu2-xS/PbS core/shell nanocrystals. Pb-oleate is mixed with 1-octadecene and heated to 60° C. Cu2-xS core solution and bis(trimethylsilyl)sulfide stock solution are added and the mixture is stirred at 60° C. for 6 minutes to form the PbS shell around the Cu2-xS nanocrystal cores. The flask is cooled and acetonitrile and toluene is added and the mixture is centrifuged to precipitate and remove the Cu2-xS/PbS core/shell nanocrystals from the reaction mixture. The reaction also produces homogeneously nucleated PbS nanocrystals, which are removed from the Cu2-xS/PbS core/shell reaction mixture via size-selective precipitation. By tailoring the amounts of Pb-oleate and bis(trimethylsilyl)sulfide stock solution in the reaction vessel, while maintaining their molar ratio of 1.5:1 and the number of Cu2-xS cores in the reaction, Cu2-xS/PbS core/shell nanocrystals having a predetermined shell thickness of PbS, and thus a predetermined level of chemical stability, can be obtained.
    Type: Application
    Filed: April 23, 2021
    Publication date: October 28, 2021
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Janice E. Boercker, Sarah F. Brittman, Joseph G. Tischler, Patrick Y. Yee, Chase T. Ellis, Paul D. Cunningham, Rhonda M. Stroud, Michael H. Stewart, Steven C. Erwin
  • Publication number: 20210324269
    Abstract: This disclosure concerns a method of making a ligand for Quantum Dot functionalization, a method of making a functionalized Quantum Dot (QD) with a ligand, and a method of making a transparent luminescent quantum dot thiol-yne nanocomposite with tailorable optical, thermal, and mechanical properties. The prepolymer solution and functionalized Quantum Dot can be used in additive manufacturing.
    Type: Application
    Filed: June 30, 2021
    Publication date: October 21, 2021
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Darryl A. Boyd, Michael H. Stewart, Kimihiro Susumu, Eunkeu Oh, James P. Wissman
  • Publication number: 20200355696
    Abstract: A construct for detecting cellular membrane potential includes a nanoparticle operable as an electron donor; a modular peptide attached to the nanoparticle, the peptide comprising a nanoparticle association domain, a motif configured to mediate peptide insertion into the plasma membrane, and at least one attachment point for an electron acceptor positioned at a controlled distance from the nanoparticle; and an electron acceptor. The nanoparticle can be a quantum dot and the electron acceptor can be C60 fullerene. Emission correlates with cellular membrane potential.
    Type: Application
    Filed: June 8, 2020
    Publication date: November 12, 2020
    Inventors: James B. Delehanty, Michael H. Stewart, Okhil Nag, Jeffrey R. Deschamps, Kimihiro Susumu, Eunkeu Oh, Lauren D. Field, Alexander L. Efros, Alan L. Huston, Igor L. Medintz, Philip E. Dawson
  • Patent number: 10780185
    Abstract: A construct for detecting cellular membrane potential includes a nanoparticle operable as an electron donor; a modular peptide attached to the nanoparticle, the peptide comprising a nanoparticle association domain, a motif configured to mediate peptide insertion into the plasma membrane, and at least one attachment point for an electron acceptor positioned at a controlled distance from the nanoparticle; and an electron acceptor. The nanoparticle can be a quantum dot and the electron acceptor can be C60 fullerene. Photoacoustic emission from the construct correlates with cellular membrane potential.
    Type: Grant
    Filed: July 10, 2018
    Date of Patent: September 22, 2020
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: James B. Delehanty, Michael H. Stewart, Okhil Nag, Jeffrey R. Deschamps, Kimihiro Susumu, Eunkeu Oh, Lauren D. Field, Alexander L. Efros, Alan L. Huston, Igor L. Medintz, Philip E. Dawson, Nashaat Rasheed, Parag V. Chitnis, John R. Cressman
  • Patent number: 10705092
    Abstract: A construct for detecting cellular membrane potential includes a nanoparticle operable as an electron donor; a modular peptide attached to the nanoparticle, the peptide comprising a nanoparticle association domain, a motif configured to mediate peptide insertion into the plasma membrane, and at least one attachment point for an electron acceptor positioned at a controlled distance from the nanoparticle; and an electron acceptor. The nanoparticle can be a quantum dot and the electron acceptor can be C60 fullerene. Emission correlates with cellular membrane potential.
    Type: Grant
    Filed: January 29, 2018
    Date of Patent: July 7, 2020
    Assignee: The Government of the United States of Americam as Represented by the Secretary of the Navy
    Inventors: James B. Delehanty, Michael H. Stewart, Okhil Nag, Jeffrey R. Deschamps, Kimihiro Susumu, Eunkeu Oh, Lauren D. Field, Alexander L. Efros, Alan L. Huston, Igor L. Medintz, Philip E. Dawson
  • Publication number: 20190330666
    Abstract: A nanoplatelet serves as a substrate for immobilizing enzymes involved in consecutive reactions as a cascade. This results in a significant increase in the rate of catalysis as well as final product yield compared to non-immobilized enzymes or enzymes immobilized to quantum dots.
    Type: Application
    Filed: June 11, 2019
    Publication date: October 31, 2019
    Inventors: Igor L. Medintz, Joyce Breger, Scott Walper, Michael H. Stewart
  • Publication number: 20190106624
    Abstract: This disclosure concerns a method of making a ligand for Quantum Dot functionalization, a method of making a functionalized Quantum Dot (QD) with a ligand, and a method of making a transparent luminescent quantum dot thiol-yne nanocomposite with tailorable optical, thermal, and mechanical properties. The prepolymer solution and functionalized Quantum Dot can be used in additive manufacturing.
    Type: Application
    Filed: October 5, 2018
    Publication date: April 11, 2019
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Darryl A. Boyd, Michael H. Stewart, Kimihiro Susumu, Eunkeu Oh, James P. Wissman
  • Publication number: 20180326097
    Abstract: A construct for detecting cellular membrane potential includes a nanoparticle operable as an electron donor; a modular peptide attached to the nanoparticle, the peptide comprising a nanoparticle association domain, a motif configured to mediate peptide insertion into the plasma membrane, and at least one attachment point for an electron acceptor positioned at a controlled distance from the nanoparticle; and an electron acceptor. The nanoparticle can be a quantum dot and the electron acceptor can be C60 fullerene. Photoacoustic emission from the construct correlates with cellular membrane potential.
    Type: Application
    Filed: July 10, 2018
    Publication date: November 15, 2018
    Inventors: James B. Delehanty, Michael H. Stewart, Okhil Nag, Jeffrey R. Deschamps, Kimihiro Susumu, Eunkeu Oh, Lauren D. Field, Alexander L. Efros, Alan L. Huston, Igor L. Medintz, Philip E. Dawson, Nashaat Rasheed, Parag V. Chitnis, John R. Cressman
  • Publication number: 20180217153
    Abstract: A construct for detecting cellular membrane potential includes a nanoparticle operable as an electron donor; a modular peptide attached to the nanoparticle, the peptide comprising a nanoparticle association domain, a motif configured to mediate peptide insertion into the plasma membrane, and at least one attachment point for an electron acceptor positioned at a controlled distance from the nanoparticle; and an electron acceptor. The nanoparticle can be a quantum dot and the electron acceptor can be C60 fullerene. Emission correlates with cellular membrane potential.
    Type: Application
    Filed: January 29, 2018
    Publication date: August 2, 2018
    Inventors: James B. Delehanty, Michael H. Stewart, Okhil Nag, Jeffrey R. Deschamps, Kimihiro Susumu, Eunkeu Oh, Lauren D. Field, Alexander L. Efros, Alan L. Huston, Igor L. Medintz, Philip E. Dawson
  • Patent number: 9304124
    Abstract: A ligand design allows compact nanoparticle materials, such as quantum dots (QDs), with excellent colloidal stability over a wide range of pH and under high salt concentrations. Self-assembled biomolecular conjugates with QDs can be obtained which are stable in biological environments. Energy transfer with these ligands is maximized by minimizing distances between QDs/nanoparticles and donors/acceptors directly attached to the ligands or assembled on their surfaces.
    Type: Grant
    Filed: July 16, 2013
    Date of Patent: April 5, 2016
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Igor L. Medintz, Kimihiro Susumu, Michael H. Stewart
  • Patent number: 8921140
    Abstract: Quantum dots are modified with varying amounts of (a) a redox-active moiety effective to perform charge transfer quenching, and (b) a fluorescent dye effective to perform fluorescence resonance energy transfer (FRET), so that the modified quantum dots have a plurality of photophysical properties. The FRET and charge transfer pathways operate independently, providing for two channels of control for varying luminescence of quantum dots having the same innate properties.
    Type: Grant
    Filed: February 6, 2014
    Date of Patent: December 30, 2014
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Igor L. Medintz, W. Russ Algar, Michael H. Stewart, Kimihiro Susumu