Trap stiffness modification of an optically trapped microsphere through directed motion of nanoparticles

Iyengar, Shruthi S.; Praveen, P. Lakshmi; Ananthamurthy, Sharath; Bhattacharya, Sarbari

doi:10.1364/ao.389500

Cited by 3 publications

(9 citation statements)

References 32 publications

(45 reference statements)

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“…The variation of the corner frequency of the trapped microsphere with nanoparticle concentration is shown in Figure 3a for the positively surface charged (cationic) nanoparticles. The results of a study carried out with negatively surface charged (anionic), but otherwise identical, nanoparticles has been reported in Iyengar et al [13] This study was repeated, using concentrations identical to that taken for the cationic charged nanoparticles, for purposes of comparison. The result of this study is shown alongside in Figure 3b.…”

Section: Resultsmentioning

confidence: 83%

“…For each of the nanoparticle concentrations, the experiment was carried out at three different laser powers. [13] The schematic of the optical tweezer setup was as shown in Figure 1. Briefly, the OT consisted of an 830 nm laser (Thorlabs), which was passed through a 1.25NA objective (Olympus).…”

Section: Methodsmentioning

confidence: 99%

“…For each of the nanoparticle concentrations, the experiment was carried out at three different laser powers. [ 13 ]…”

Section: Methodsmentioning

confidence: 99%

“…κ could be seen to scale linearly with the corner frequency as long as the drag coefficient remains a constant, which was indeed the case here. [ 13 ] The discussions of the results of this study, thereby, were carried out in terms of the corner frequency rather than the trap stiffness.…”

Section: Methodsmentioning

confidence: 99%

“…These results are compared with that of studies carried out with suspensions of nanoparticles with negative surface charge. [ 13 ]…”

Section: Introductionmentioning

confidence: 99%

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Effect of Surface Charge on a Microsphere on the Stability of a Nanoparticle Suspension

Iyengar,

Bhattacharya

2024

Macromolecular Symposia

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A stable suspension of nanoparticles is generally achieved by modifying the surface properties of the nanoparticles using a surfactant. This is to create a surface charge on the nanoparticles which prevents them from forming aggregates. This phenomenon is very sensitive to changes in the local environment. Conventional optical tweezers though capable of trapping sub‐micrometer particles are not known to trap single nanoparticles. However, the stability and dynamics of a suspension of nanoparticles can be probed through the changes in the fluctuations of an optically trapped microsphere that has been added to the suspension. Adding microspheres to the nanoparticle suspension can affect the stability depending on the surface charges the microparticles themselves have. The study reports here on the variation of the dynamics of suspended nanoparticles, which have a positive surface charge, when silica microspheres, which are negatively surface charged, are added to the suspension. With the addition of silica beads, there is agglomeration of the nanoparticles. The dynamics of these agglomerated structures are then probed by measuring the Brownian fluctuations of an optically trapped silica bead. These results are in sharp contrast to those of earlier studies carried out with suspensions of identical nanoparticles but with negative surface charge.

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Section: Resultsmentioning

confidence: 83%

Section: Methodsmentioning

confidence: 99%

“…For each of the nanoparticle concentrations, the experiment was carried out at three different laser powers. [ 13 ]…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…These results are compared with that of studies carried out with suspensions of nanoparticles with negative surface charge. [ 13 ]…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effect of Surface Charge on a Microsphere on the Stability of a Nanoparticle Suspension

Iyengar,

Bhattacharya

2024

Macromolecular Symposia

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Fast and versatile optical force measurement with digitally modulated stimulus in holographic optical tweezers

Liu¹,

Qu²,

Zhao³

et al. 2023

Optics & Laser Technology

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Improving the multi-functionality of optical tweezers with FPGA integration

Liu,

Fan,

et al. 2023

Appl. Opt.

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The development of optical tweezers aims to extend their operating function and pattern. However, excessive programming can lead to a decrease in the system’s operating speed and introduce bugs or data transmission delays. In this study, we present a time-shared optical tweezers system that allows for parallel operation of multiple functions. To enable efficient data transmission, we employ a queue structure and a buffer. To assess the system’s performance, we utilize a biological sample in conjunction with the optical tweezers system and scanning imaging technique. We quantify the trapping parameter while concurrently running power stabilization programs. As a result, the standard deviation of the measured stiffness is reduced by 60% in the x and y directions and 30% in the z direction, indicating a significant improvement in calibration precision. Throughout the program execution, the system maintains an operating rate of 110 kHz, and the data are continuously updated in real time on the host. The system’s performance demonstrates its potential for quantification and morphological reconstruction of biological samples.

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Trap stiffness modification of an optically trapped microsphere through directed motion of nanoparticles

Cited by 3 publications

References 32 publications

Effect of Surface Charge on a Microsphere on the Stability of a Nanoparticle Suspension

Effect of Surface Charge on a Microsphere on the Stability of a Nanoparticle Suspension

Fast and versatile optical force measurement with digitally modulated stimulus in holographic optical tweezers

Improving the multi-functionality of optical tweezers with FPGA integration

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