Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > In latest generation of tiny biosensors, size isn't everything: UCLA researchers overturn conventional wisdom on nanowire-based diagnostic devices

Abstract:
When it comes to nanomedicine, smaller is surprisingly not always better.

UCLA Henry Samueli School of Engineering and Applied Science researchers have determined that the diminutive size of nanowire-based biosensors which healthcare workers use to detect proteins that mark the onset of heart failure, cancer and other health risks is not what makes them more sensitive than other diagnostic devices. Rather, what matters most is the interplay between the charged ions in the biological sample being tested and the charged proteins captured on the sensors' surface.

In latest generation of tiny biosensors, size isn't everything: UCLA researchers overturn conventional wisdom on nanowire-based diagnostic devices

Los Angeles, CA | Posted on April 11th, 2014

The finding counters years of conventional wisdom that a biosensor can be made more sensitive simply by reducing the diameter of the nanowires that make up the device. This assumption has driven hundreds of costly research-and-development efforts in the field of nanomedicine in which tiny materials and devices are used to detect, diagnose and treat disease.

The research suggests new directions for designing biosensors to improve their sensitivity and make them more practical for doctors and, eventually, patients themselves to use.

"This is the first time the understanding of why nanowire biosensing works has been challenged," said Chi On Chui, an associate professor of electrical engineering and bioengineering at UCLA whose lab performed the research. "The advantage is not from the fact that the wires are nanoscale, but rather how their geometry reduces the ability of the ions to inhibit protein detection. This research could be a step toward developing sophisticated, cost-efficient and portable devices to accurately detect a range of illnesses."

The research was published March 25 in the Proceedings of the National Academy of Sciences.

Nanowire biosensors are, in essence, electronic transistors with a diameter smaller than the width of a single red blood cell. When they are exposed to a sample of blood or another bodily fluid, the specific charged proteins being tested for are captured on the nanowires' surfaces. The charge of the captured proteins changes the rate of electric current flowing through the nanowire transistor. By monitoring the electrical current, researchers can quantify the concentration of proteins in the sample, which can give them an indication of heart health, diabetes and a number of other medical conditions.

A challenge to the practical use of the technology is that in addition to the charged proteins, many physiological fluids contain a large concentration of charged ions, such as sodium, potassium and chloride. These ions surround the proteins and mask the protein charge, which prevents the sensor from detecting the proteins.

Researchers in labs can circumvent this problem. But doctors performing tests on their patients or patients monitoring their own health at home cannot do so without the assistance of a technician. This has hampered the adoption of the technology.

The UCLA research advances understanding of nanowire efficiency in several ways. First, it proves that the small size of the nanowires is not inherently responsible for the fact that they outperform their planar counterparts.

Second, it demonstrates that the improvement in performance results from the fact that ionic screening is reduced in tight spaces such as the corners between a nanowire and the base it sits on because ions have difficulty approaching proteins there. This corner effect exists in most biosensing structures, whether they are nanoscale or not; but the effect becomes more important at the nanoscale.

The research also shows that in general, devices with concave surfaces work more efficiently than those with convex surfaces.

"My hope is that researchers can use this understanding to do two things," said Kaveh Shoorideh, the UCLA Engineering graduate student who is first author of the research. "First, to make sensitive biosensors without resorting to expensive nanowires, and second, to come up with ways to reduce ionic screening without requiring a technician."

The research was supported by the National Science Foundation.

####

About UCLA
The UCLA Henry Samueli School of Engineering and Applied Science, established in 1945, offers 28 academic and professional degree programs and has an enrollment of more than 5,000 students. The school's distinguished faculty are leading research to address many of the critical challenges of the 21st century, including renewable energy, clean water, health care, wireless sensing and networking, and cyber-security. Ranked among the top 10 engineering schools at public universities nationwide, the school is home to eight multimillion-dollar interdisciplinary research centers in wireless sensor systems, wireless health, nanoelectronics, nanomedicine, renewable energy, customized computing, the smart grid, and the Internet, all funded by federal and private agencies and individual donors.

For more information, please click here

Contacts:
Bill Kisliuk

310-206-0540

Copyright © UCLA

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Video captures bubble-blowing battery in action: Researchers propose how bubbles form, could lead to smaller lithium-air batteries April 26th, 2017

New Product Nanoparticle preparation from Intertronics with new Thinky NP-100 Nano Pulveriser April 26th, 2017

California Research Alliance by BASF establishes more than 25 research projects in three years April 26th, 2017

Affordable STM32 Cloud-Connectable Kit from STMicroelectronics Puts More Features On-Board for Fast and Flexible IoT-Device Development April 26th, 2017

Govt.-Legislation/Regulation/Funding/Policy

Graphene holds up under high pressure: Used in filtration membranes, ultrathin material could help make desalination more productive April 24th, 2017

Nanoparticle vaccine shows potential as immunotherapy to fight multiple cancer types April 24th, 2017

NanoMONITOR shares its latest developments concerning the NanoMONITOR Software and the Monitoring stations April 21st, 2017

Better living through pressure: Functional nanomaterials made easy April 19th, 2017

Nanomedicine

New Product Nanoparticle preparation from Intertronics with new Thinky NP-100 Nano Pulveriser April 26th, 2017

Nanoparticle vaccine shows potential as immunotherapy to fight multiple cancer types April 24th, 2017

Arrowhead Presents ARC-520 and ARC-521 Clinical Data at The International Liver Congress(TM) April 20th, 2017

Nano-SPEARs gently measure electrical signals in small animals: Rice University's tiny needles simplify data gathering to probe diseases, test drugs April 17th, 2017

Sensors

Better living through pressure: Functional nanomaterials made easy April 19th, 2017

A Sensitive And Dynamic Tactile Sensor Read more from Asian Scientist Magazine at: https://www.asianscientist.com/2017/04/tech/tactile-3d-active-matrix-sensor/ April 18th, 2017

AIM Photonics Presents Cutting-Edge Integrated Photonics Technology Developments to Packed House at OFC 2017, the Optical Networking and Communication Conference & Exhibition April 11th, 2017

New technology could offer cheaper, faster food testing: Specialized droplets interact with bacteria and can be analyzed using a smartphone April 7th, 2017

Discoveries

Geoffrey Beach: Drawn to explore magnetism: Materials researcher is working on the magnetic memory of the future April 25th, 2017

Using light to propel water : With new method, MIT engineers can control and separate fluids on a surface using only visible light April 25th, 2017

Graphene holds up under high pressure: Used in filtration membranes, ultrathin material could help make desalination more productive April 24th, 2017

Nanoparticle vaccine shows potential as immunotherapy to fight multiple cancer types April 24th, 2017

Announcements

Video captures bubble-blowing battery in action: Researchers propose how bubbles form, could lead to smaller lithium-air batteries April 26th, 2017

New Product Nanoparticle preparation from Intertronics with new Thinky NP-100 Nano Pulveriser April 26th, 2017

California Research Alliance by BASF establishes more than 25 research projects in three years April 26th, 2017

Affordable STM32 Cloud-Connectable Kit from STMicroelectronics Puts More Features On-Board for Fast and Flexible IoT-Device Development April 26th, 2017

Nanobiotechnology

Nanoparticle vaccine shows potential as immunotherapy to fight multiple cancer types April 24th, 2017

Arrowhead Presents ARC-520 and ARC-521 Clinical Data at The International Liver Congress(TM) April 20th, 2017

Nano-SPEARs gently measure electrical signals in small animals: Rice University's tiny needles simplify data gathering to probe diseases, test drugs April 17th, 2017

Nanotubes that build themselves April 14th, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project