Using the NanoTweezer for Nanomanipulation

Topics Covered

Optofluidics’ NanoTweezer
Working Principle of NanoTweezer
Applications of NanoTweezer
Advantages of NanoTweezer
About Optofluidics Incorporated

Optofluidics’ NanoTweezer

The NanoTweezer technology of Optofluidics allows users to access and observe individual cells, viruses, and biomolecules in real time using their available microscopy tools. It has a microfluidic infrastructure that enables introduction of new agents into the trapped particle such as antibodies and simultaneous manipulation of the environmental conditions such as pH.

Working Principle of NanoTweezer

The ability of conventional optical tweezers to manipulate microscale objects has been well established. However, the forces applied by these devices are not sufficient to trap tiny dielectric objects in a high-speed flow. Hence, they are not recommended for high throughput applications. Optofluidics' NanoTweezer System and Chips tackle the technical issues related to robust fluidic and optical coupling by directly integrating optical resonance through the use of 1064nm excitation for low heating and silicon nitride manufacturing.

Compared to conventional methods, Optofluidics’ patented Photonic Resonance Trapping technology traps nanoparticles and other materials that are tinier and more different (Figure 1). For this purpose, it applies the evanescent field surrounding a nanophotonic waveguide on the company’s chips (Figure 2). The evanescent field is a halo that decays exponentially. It has a unique combination of extremely sharp gradients and high optical intensity, which drastically increases the trapping forces.

Figure 1. Exploiting near-field optical manipulation using the NanoTweezer enables trapping and manipulation of significantly smaller objects than with traditional optical tweezers.

Figure 2. Comparison between traditional free-space optical tweezing and Optofluidics' patented Photonic Resonance based technique.

Applications of NanoTweezer

The NanoTweezer can be used in the following life science applications:

  • Rapid immunoassay development
  • Single virus binding and phage entrance studies
  • Cell and bacteria trapping
  • Micelle and liposome analysis
  • Nanoparticle drug release studies

The following are the materials science applications of the NanoTweezer:

  • Nanoparticle synthesis and analysis
  • Directed nanoassembly of hybrid nanostructures
  • Optical interaction analysis

Advantages of NanoTweezer

Compared to conventional tweezers, Optofluidics' NanoTweezer system not only facilitates trapping tinier and more different objects, but also supports simultaneous manipulation and analysis. Figure 3 demonstrates the trapping and accumulation of polymer nanoparticles having a diameter of 100nm in a fast flow by the NanoTweezer.

The trapping rate measured was to be 5 particles/s. The last two frames reveal the release of particles subsequent to turning off the laser, confirming the non-specific trapping of the particles. As shown in Figure 3, the evanescent field interacts with a particle that flows over the waveguide and attracts it towards the waveguide. Besides polymer nanoparticles, other targets are protein aggregates, pharmaceutical formulations, and semiconductor and metal beads.

Figure 3. Demonstration of 100nm particle trapping and accumulation in high-speed flow.

The NanoTweezer can also be used for nucleic acid based force spectroscopy, thanks to its accurate flow control, high stability and surface-based nanoparticle trapping. It facilitates stretching of DNA based on the flow (Figure 4). The DNA is tethered between a large bead and a metallic nanoparticle that is trapped on the waveguide. The application of larger drag on the bead by the flow subjects the DNA to an elongation force. It is possible to apply very high forces owing to the metallic bead’s strong trapping stability.

Figure 4. By tethering DNA to a metallic nanoparticle and a large polystyrene bead, very high stretching forces can be obtained.

The following video demonstrates the ability of the NanoTweezer to carry out the analysis simultaneously along a single waveguide. This, in turn, improves the throughput of the analysis.

High throughput force spectroscopy on individual nucleic acids

About Optofluidics Incorporated

Optofluidics, Inc. is a venture backed life-sciences company that is developing microfluidic and biophotonic nanomanipulation technologies for biological, material science, and pharmaceutical applications.

Our investors and development partners include BioAdvance, the National Science Foundation, the Defense Advanced Research Projects Agency, and the Ben Franklin NanoTechnology Institute.

In 2012 Optofluidics was named Philadelphia Life Sciences startup of the year.

This information has been sourced, reviewed and adapted from materials provided by Optofluidics Incorporated.

For more information on this source, please visit Optofluidics Incorporated.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback