Optical tweezers have been widely used in the study of the physical and chemical properties of individual aerosol particles. However, the traditional method of using optical tweezers can only measure one particle at a time, which limits the efficiency and throughput of the measurement. Although the method of using a spatial light modulator (SLM) to simultaneously generate multiple optical traps has been developed, which adds significant complexity to the overall optical setup including the need for precise alignment of the SLM, integration with the trapping laser, and the implementation of algorithms to generate the desired multi-trap patterns. This research proposes a method for the simultaneous measurement of multiple aerosol particles based on optical tweezers. The method uses multiple combinations of polarization beam splitters and half-wave plates to generate multiple optical traps, which can capture and manipulate multiple aerosol particles simultaneously. The proposed method has the advantages of improved trapping efficiency, faster temporal control and reduced aberrations, which provides a new tool for the study of multiple aerosol particles properties and behavior.
Radiation at terahertz frequencies can be used to analyze the structural dynamics of water and biomolecules, but applying the technique to aqueous solutions and tissues remains challenging since terahertz radiation is strongly absorbed by water. While this absorption enables certain analyses, such as the structure of water and its interactions with biological solutes, it limits the thickness of samples that can be analyzed, and it drowns out weaker signals from biomolecules of interest. We present a method for analyzing water-rich samples via time-domain terahertz optoacoustics over a 104-fold thickness ranging from microns to centimeters. We demonstrate that adjusting the temperature to alter the terahertz optoacoustic (THz-OA) signal of water improves the sensitivity with which it can be analyzed and, conversely, can reduce or even “silence” its signal. Temperature-manipulated THz-OA signals of aqueous solutions allow detection of solutes such as ions with an order of magnitude greater sensitivity than terahertz time-domain spectroscopy, and potentially provide more characteristic parameters related to both terahertz absorption and ultrasonic propagation. Terahertz optoacoustics may be a powerful tool for spectroscopy and potential imaging of aqueous solutions and tissues to explore molecular interactions and biochemical processes.
Optical tweezers is one of the commonly used technologies to research on protein force spectroscopy. However, whether optical tweezers system has the capability of force spectroscopy measurement at the molecular scale is vital to single molecule experiments. In this paper, we test the capability of our home-built dual-trap optical tweezers system by stretching polyprotein (NuG2)8 which is made of eight identical tandem repeats of NuG2. With the constant velocity stretching and relaxation mode, we achieve a lot of experimental data and get the contour length increment of (NuG2)8 rapidly from the unfolding processes after fitting these data. The result is consistent with existing reports, which demonstrates optical tweezers system has the force spectroscopy test ability and (NuG2)8 can be used as a new standard sample to evaluate the test performance of optical tweezers. Using polyprotein (NuG2)8 as standard sample has two advantages: stretching polyprotein can help improve the efficiency of data statistics and a large number of experiments can reduce the randomness of the system when testing.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.