Sensor system and methods of making

Inventors

Khosravi, Farhad • Bastable, David • Dryga, Sergey A.

Assignees

NanoDx Inc

Abstract

Sensors having an advantageous design and methods for fabricating such sensors are generally provided. Some sensors described herein comprise pairs of electrodes having radial symmetry, pairs of nested electrodes, and/or nanowires. Some embodiments relate to fabricating electrodes by methods in which nanowires are deposited from a fluid contacted with a substrate in a manner such that it evaporates and is replenished.

Core Innovation

The invention provides a method of depositing a plurality of nanowires onto a substrate by expelling a fluid comprising the plurality of nanowires from a nozzle onto the substrate. At least a portion of the fluid evaporates, and at least a portion of the evaporated fluid is replenished by expelling a further amount of the fluid from the nozzle. The fluid is held in contact with the substrate for a time period greater than or equal to 0.2 sec.

In the deposition method, the fluid is in contact with both the substrate and the nozzle during the holding, replenishing, and evaporation steps. The described sensor system includes nanowires electrically connecting electrode pairs, arranged as an electrode-pair array with radial symmetry around a center point, including up to ten pairs, with optional nested electrode geometries and spacing/dimension relationships enabling nanowire-mediated electrical communication.

The sensor design further includes blocking and passivating layers to reduce nonspecific interactions and charge screening, and the device context includes integration with additional electrodes such as a back gate electrode, a water gate electrode, and a ground electrode. The nanowires are functionalized with binding entities, including antibodies and biomarker targets such as GFAP, UCH-L1, S100β, ICH, NFL-1, and SARS-CoV-2 spike, and the document discusses improved sensing behavior using time-varying equivalent surface potential.

The described deposition fabricates circular nanowire structures associated with evaporation effects, including coffee-ring/circular nanowire structures, using a nozzle-deposited nanowire fluid that is replenished while in contact with the substrate and the nozzle for at least 0.2 sec. Example results described include improved pH response based on amine/surface chemistry changes and biomarker binding effects for binding targets such as S100β and SARS-CoV-2 detection in saliva.

Claims Coverage

The independent claim covers one inventive feature centered on a nozzle-based nanowire deposition method with evaporation, replenishing, and a holding period of at least 0.2 sec. The provided content also references dependent refinements relating to electrode-pair counts, sensor architectures, fluid constraints, and bodily-fluid contexts.

The claim coverage focuses on a deposition approach that couples nozzle expelling, evaporation, replenishing by further nozzle expelling, and a holding period of at least 0.2 sec while the fluid simultaneously contacts both the substrate and the nozzle during evaporation and replenishing.

Stated Advantages

Documented Applications