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 Scientists channel graphene to understand filtration and ion transport into cells
11.12.2017 | National Institute of Standards and Technology (NIST)

nachricht Successful Mechanical Testing of Nanowires
07.12.2017 | Helmholtz-Zentrum Geesthacht - Zentrum für Material- und Küstenforschung

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Gecko adhesion technology moves closer to industrial uses

13.12.2017 | Information Technology

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure

13.12.2017 | Physics and Astronomy

Research reveals how diabetes in pregnancy affects baby's heart

13.12.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>