Electrochemical approach for cancer detection

Patent metadata

Field	Value
Publication number	US-2016356739-A1
Application number	US-201615238795-A
Country	US
Kind code	A1
Filing date	Aug 17, 2016
Priority date	Dec 5, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

An electrical probe configured to measure an electrical response from a biological cell includes a microwire having a sharpened tip, a catalyst layer formed on the sharpened tip of the microwire, and an array of nanotube electrodes vertically aligned on the catalyst layer.

First claim

What is claimed is:

1 - An electrical probe for measuring an electrical response from a biological cell, comprising:
a microwire having a sharpened tip section, a catalyst layer formed on the sharpened tip section of the microwire; and an array of nanotube electrodes vertically aligned on the catalyst layer,
wherein, the array of nanotube electrodes are configured to measure the electrical response of the biological cell in contact with the electrodes.

2 - The electrical probe according to claim 1 , wherein one of the nanotube electrodes is located on a tip of the sharpened tip section and is longer than remaining nanotube electrodes of the nanotube electrodes.

3 - The electrical probe according to claim 1 , wherein the microwire includes a tungsten microwire.

4 - The electrical probe according to claim 2 , wherein the microwire has a diameter less than 2000 μm.

5 - The electrical probe according to claim 1 , wherein a tip of the sharpened tip section of the microwire has a diameter about 200 nm.

6 - The electrical probe according to claim 1 , wherein the catalyst layer includes a bilayer catalyst having a Nickel layer (Ni) and a Gold layer (Au).

7 - The electrical probe according to claim 6 , wherein the Gold layer (Au) has a thickness in a range of 1 nm to 4 nm and the Nickel layer (Ni) has a thickness in a range of 10 nm to 40 nm.

8 - The electrical probe according to claim 1 , wherein the nanotube electrodes include a plurality of silicone nanotubes (SiNTs).

9 - A method for fabricating a tungsten (W) supported silicon nanotube (SiNT) based electrical probe (SiNT/W probe) comprising steps of:
sharpening one end of a tungsten (W) microwire to form a tungsten (W) needle having a sharpened tip section; forming a catalyst bilayer on the sharpened tip section of the tungsten (W) needle; growing a plurality of silicon nanotubes (SiNTs) on the catalyst bilayer to form a SiNT/W needle; doping the SiNT/W needle using a doping furnace to form a doped conductive SiNT/W needle; and coating a gold layer on top of the SiNTs of the doped conductive SiNT/W needle to form a SiNT/W probe,
wherein the electrical probe is configured to measure an electrical response of a biological cell contacting the silicon nanotubes (SiNTs).

10 - The method according to claim 9 , wherein a silicon nanotube located on a tip of the sharpened tip section is longer than remaining silicon nanotubes of the plurality of silicon nanotubes (SiNTs).

11 - The method according to claim 9 , wherein sharpening the one end of a tungsten (W) microwire is done via an electrochemical etching process.

12 - The method according to claim 9 , wherein the tungsten (W) needle is cleaned via immersion in a solution including acetone and buffer HF.

13 - The method according to claim 9 , wherein forming a catalyst bilayer on the sharpened tip section of the tungsten (W) needle includes a two-step deposition process using an electron beam coating system, the process comprising:
holding the tungsten (W) needle under a gold plume to coat a layer of gold on the sharp tip to form a first catalyst layer; and holding the tungsten (W) needle having the first catalyst layer under a Nickel plume to coat a layer of Nickel over the first catalyst layer to form the catalyst bilayer (Ni-Au) on the sharp tip of the tungsten (W) needle.

14 - The method according to claim 9 , wherein growing the plurality of SiNTs includes growing the plurality of SiNTs via a vapor-solid-liquid (VLS) process using a Low-Pressure Chemical Vapor Deposition (LPCVD) system.

15 - The method according to claim 13 , wherein:
the VLS process is done using H 2 and SiH 4 gases; and the VLS process is done at a temperature range of about 400° C. to 600° C.

16 - The method according to claim 13 , wherein the VLS process is done at a pressure of about 1 mTorr.

17 - The method according to claim 9 , wherein the doping furnace includes a phosphorous doping furnace.

18 - The method according to claim 17 , wherein the SiNT/W needle is held in the phosphorous doping furnace at a temperature of about 700° C. for about 10 minutes.

19 - The method according to claim 9 , wherein coating a gold layer on top of the SiNTs of the doped conductive SiNT/W needle is done using a sputtering system.

20 - The method according to claim 20 , wherein the gold layer has a thickness of 5 nm.

Assignees

• Abdolahad Mohammad
• Saeidi Ali
• Gharooni Milad

Inventors

• Abdolahad Mohammad
• Saeidi Ali
• Gharooni Milad

Classifications

• C25F3/08

  of refractory metals · CPC title

• G01N27/028

  Circuits therefor (measuring impedance per se G01R27/02) · CPC title

• C23C28/322

  only coatings of metal elements only · CPC title

• C23C28/321

  with at least one metal alloy layer · CPC title

• C23C14/16

  on metallic substrates or on substrates of boron or silicon · CPC title