University of Minnesota

Boston Scientific Scimed, Inc.

Xue Zhen

Philippe Pierre Joseph Buhlmann

Steven John Koester

Justin Theodore Nelson

Gregory J Sherwood

Jinbo Hu

Philippe Buhlmann

Andreas Stein

Yao Zhang

Qun Su

Blair K Troudt

Embodiments herein relate to systems and methods for utilizing hysteresis as a mechanism of analysis of a sample. A system for analyzing a fluid sample is included having a controller circuit and a chemical sensor element. The chemical sensor element can include one or more discrete binding detectors that can include one or more graphene varactors. The system can include measurement circuitry having an electrical voltage generator configured to generate an applied voltage at a plurality of voltage values to be applied to the one or more graphene varactors. The system can include a measurement circuit having a capacitance sensor configured to measure capacitance of the discrete binding detectors resulting from the applied voltage. The system for analyzing the fluid sample can be configured to measure hysteresis effects related to capacitance versus voltage values obtained from the one or more graphene varactors. Other embodiments are also included herein.

Systems utilizing graphene varactor hysteresis effects for sample characterization

Embodiments herein relate to chemical sensors based on the non-covalent surface modification of graphene with compounds containing hydrazine or hydroxylamine functional groups for the detection of aldehyde and ketone-bearing analytes. In an embodiment, a medical device is included having a graphene varactor included a graphene layer and a self-assembled monolayer disposed on an outer surface of the graphene layer through electrostatic interactions between a partial positive charge on hydrogen atoms of one or more hydrocarbons of the self-assembled monolayer and a π-electron system of graphene. The self-assembled monolayer can include one or more compounds having one or more hydrazine groups or hydroxylamine groups, substituted hydrazine or hydroxylamine groups, or derivatives thereof. Other embodiments are also included herein.

Aldehyde and ketone receptor modification of graphene

Chemical sensors, devices and systems including the same, and related methods are disclosed. In an embodiment, a medical device is included having a graphene varactor including a graphene layer and a self-assembled monolayer disposed on an outer surface of the graphene layer through non-covalent interactions between the self-assembled monolayer and a π-electron system of graphene. The self-assembled monolayer includes one or more pillarenes, substituted pillarenes, calixarenes, substituted calixarenes, peralkylated cyclodextrins, substituted peralkylated cyclodextrins, pyrenes, or substituted pyrenes, or derivatives of each. Other embodiments are also included.

Non-covalent modification of graphene-based chemical sensors

Embodiments include chemical sensors, devices and systems including the same, and related methods. In an embodiment, a medical device is provided. The medical device can include a graphene varactor, including a graphene layer and a self-assembled monolayer disposed on an outer surface of the graphene layer through electrostatic interactions between a partial positive charge on hydrogen atoms of one or more hydrocarbons of the self-assembled monolayer and a π-electron system of graphene. The self-assembled monolayer can include one or more substituted porphyrins or substituted metalloporphyrins, or derivatives thereof. Other embodiments are also included herein.

Chemical sensors with non-covalent, electrostatic surface modification of graphene

Solid-contact electrodes include a molecular redox buffer that is covalently attached to one of the components of the electrodes. These electrodes can be incorporated into electrochemical sensor systems. The electrode components are an electron conductor, a membrane and optionally, an interlayer. The electrode includes covalent attachment of the molecular redox buffer to the interlayer, to the electron conductor or the membrane. The interlayer includes nanoporous carbon such as CIM-carbon. The molecular redox buffer includes a well-defined redox pair, e.g., a complex of Co(II)/Co(III). The electrodes are ion-selective electrodes (ISEs) or reference electrodes. Methods include constructing solid contact electrodes and using the electrodes in electrochemical sensor systems to determine the quantity of an analyte in a sample. The electrochemical sensor systems include disposable paper-based devices and/or wearable devices for measuring analytes in a sample.

Electrochemical sensors with a chemically attached molecular redox buffer

Embodiments include chemical sensors, devices and systems including the same, and related methods. In an embodiment, a medical device is provided. The medical device can include a graphene varactor, including a graphene layer and a self-assembled monolayer disposed on an outer surface of the graphene layer through electrostatic interactions between a partial positive charge on hydrogen atoms of one or more hydrocarbons of the self-assembled monolayer and a it-electron system of graphene. The self-assembled monolayer can include one or more substituted porphyrins or substituted metalloporphyrins, or derivatives thereof. Other embodiments are also included herein.

Embodiments herein relate to chemical sensors, devices and systems including the same, and related methods. In an embodiment, a medical device is included. The medical device can include a graphene varactor. The graphene varactor can include a graphene layer and a self-assembled monolayer disposed on an outer surface of the graphene layer through &#x3c0;-&#x3c0; stacking interactions. The self-assembled monolayer can provide a Langmuir theta value of at least 0.9. The self-assembled monolayer can include polycyclic aromatic hydrocarbons, tetraphenylporphyrins or derivatives thereof, metallotetraphenylporphyrins, or aromatic cyclodextrins. Other embodiments are also included herein.

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Minneapolis, MN, United States of America

Xue Zhen