Featured Research

from universities, journals, and other organizations

Hot spots for molecules: Ultra-high sensitivity molecular detection

Date:
June 5, 2014
Source:
The Agency for Science, Technology and Research (A*STAR)
Summary:
The accurate placement of molecules into gaps between gold nanoantennas enables ultra-high sensitivity molecular detection. The ability to detect tiny quantities of molecules is important for chemical sensing as well as biological and medical diagnostics. In particular, some of the most challenging and advanced applications involve rare compounds for which only a few molecules may be present at a time. The most promising devices for achieving ultrahigh-precision detection are nanoscale sensors, where molecules are placed in tiny gaps between small gold plates.

Titanium pads (pink) placed in the ‘hot spots’ (red) between oval gold plates can be used to sense tiny amounts of molecules (blue).
Credit: Copyright 2014 A*STAR Institute of Materials Research and Engineering

The accurate placement of molecules into gaps between gold nanoantennas enables ultra-high sensitivity molecular detection.

The ability to detect tiny quantities of molecules is important for chemical sensing as well as biological and medical diagnostics. In particular, some of the most challenging and advanced applications involve rare compounds for which only a few molecules may be present at a time. The most promising devices for achieving ultrahigh-precision detection are nanoscale sensors, where molecules are placed in tiny gaps between small gold plates. But this method is effective only if the molecules are positioned accurately within the gaps. Now, Jinghua Teng from the A*STAR Institute of Materials Research and Engineering, Singapore, and colleagues from the National University of Singapore, have developed a sensor where molecules are efficiently guided and placed into position.

The electronic resonances occurring in gold nanostructures are like very powerful antennas, able to amplify radiation from small molecules in their vicinity. This permits even the detection of single molecules. In order for the signal to be picked up by the antennas, however, the molecules need to be precisely located within electromagnetic 'hot spots' (see image). "We approached this challenge and developed a method to selectively bind the molecules to the electromagnetic hot spots in the nanoantenna structure for maximum effect," explains Teng.

The researchers needed to prepare the device surface such that the molecules bind only to the desired areas between the gold plates -- not on them. They achieved this by depositing a thin titanium film between the gold plates. The titanium oxidizes in air, forming stable titanium dioxide, which is insulating and has very different properties to the gold plates. The researchers then covered the surface with various organic solutions that selectively prevent proteins and other molecules from binding to the gold while attracting the molecules of interest to the titanium pad. In initial tests, signals from molecules attached to the titanium in the hot spot showed a six times higher sensitivity than those randomly attached across the device.

The next step will be to increase the sensor sensitivity to the ultimate limit, explains Teng. "People have been dreaming of and working toward single-molecule sensing. This work is part of these efforts. It provides a way to selectively bind biomolecules to the hot spots and proves that it can enhance the molecular sensitivity and reduce the amount of sample required." Further improvements in device design will however be required, adds Teng. "Moving forward, we would like to further push the sensitivity by optimizing the structure and try multi-agent sensing in one chip."


Story Source:

The above story is based on materials provided by The Agency for Science, Technology and Research (A*STAR). Note: Materials may be edited for content and length.


Journal Reference:

  1. Nan Zhang, Yan Jun Liu, Jing Yang, Xiaodi Su, Jie Deng, Chan Choy Chum, Minghui Hong, Jinghua Teng. High sensitivity molecule detection by plasmonic nanoantennas with selective binding at electromagnetic hotspots. Nanoscale, 2014; 6 (3): 1416 DOI: 10.1039/C3NR04494G

Cite This Page:

The Agency for Science, Technology and Research (A*STAR). "Hot spots for molecules: Ultra-high sensitivity molecular detection." ScienceDaily. ScienceDaily, 5 June 2014. <www.sciencedaily.com/releases/2014/06/140605113320.htm>.
The Agency for Science, Technology and Research (A*STAR). (2014, June 5). Hot spots for molecules: Ultra-high sensitivity molecular detection. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2014/06/140605113320.htm
The Agency for Science, Technology and Research (A*STAR). "Hot spots for molecules: Ultra-high sensitivity molecular detection." ScienceDaily. www.sciencedaily.com/releases/2014/06/140605113320.htm (accessed September 22, 2014).

Share This



More Matter & Energy News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Thousands March in NYC Over Climate Change

Thousands March in NYC Over Climate Change

AP (Sep. 21, 2014) — Accompanied by drumbeats, wearing costumes and carrying signs, thousands of demonstrators filled the streets of Manhattan and other cities around the world on Sunday to urge policy makers to take action on climate change. (Sept. 21) Video provided by AP
Powered by NewsLook.com
What This MIT Sensor Could Mean For The Future Of Robotics

What This MIT Sensor Could Mean For The Future Of Robotics

Newsy (Sep. 20, 2014) — MIT researchers developed a light-based sensor that gives robots 100 times the sensitivity of a human finger, allowing for "unprecedented dexterity." Video provided by Newsy
Powered by NewsLook.com
MIT BioSuit A New Take On Traditional Spacesuits

MIT BioSuit A New Take On Traditional Spacesuits

Newsy (Sep. 19, 2014) — The MIT BioSuit could be an alternative to big, bulky traditional spacesuits, but the concept needs some work. Video provided by Newsy
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) — Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins