Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hot spots for molecules

06.06.2014

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.


Titanium pads (pink) placed in the ‘hot spots’ (red) between oval gold plates can be used to sense tiny amounts of molecules (blue).

Copyright : © 2014 A*STAR Institute of Materials Research and Engineering

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 [1].

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.

... more about:
»A*STAR »binding »explains »sensitivity »small »structure »tiny »titanium

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.”


Reference

1. Zhang, N., Liu, Y. J., Yang, J., Su, X., Deng, J. et al. High sensitivity molecule detection by plasmonic nanoantennas with selective binding at electromagnetic hotspots. Nanoscale 6, 1416–1422 (2014).

Associated links

A*STAR Research | Research SEA News
Further information:
http://www.research.a-star.edu.sg/research/6981
http://www.researchsea.com

Further reports about: A*STAR binding explains sensitivity small structure tiny titanium

More articles from Materials Sciences:

nachricht Sequencing the DNA of Things with the Materials Genomics Initiative
30.03.2015 | West Virginia University - Eberly College of Arts and Sciences

nachricht Electrifying Research: Piezoelectric Effects for the Suppression of Material Stresses
30.03.2015 | Austrian Science Fund FWF

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energy-autonomous and wireless monitoring protects marine gearboxes

The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.

As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...

Im Focus: 3-D satellite, GPS earthquake maps isolate impacts in real time

Method produced by UI researcher could improve reaction time to deadly, expensive quakes

When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.

Im Focus: Atlantic Ocean overturning found to slow down already today

The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe. 

Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...

Im Focus: Robot inspects concrete garage floors and bridge roadways for damage

Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.

From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

10. CeBiTec Symposium zum Big Data-Problem

17.03.2015 | Event News

 
Latest News

Speech dynamics are coded in the left motor cortex

31.03.2015 | Life Sciences

100-million-year-old scale insect practiced brood care

31.03.2015 | Life Sciences

Discovery of two new species of primitive fishes discovered

31.03.2015 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>