We have a new paper appearing in Optics Letters on optical manipulation of fluorescent nano-diamonds. This experimental work (with some simulations) was performed by our group member Ashutosh Shukla in collaboration with the group of Prof. Kasturi Saha (IIT-Bombay). Our alumni, Sunny Tiwari, gave vital inputs to perform the experiments.
Fluorescent nano-diamonds have emerged as important (quantum) imaging agents in biological applications. It remains a challenge to manipulate them in complex fluidic environments.
Herein, we have come up with an optical trapping method based on opto-thermoelectric effect (see Fluorescence imaging video above). By using opto-thermal potentials created by a single gold nanoparticle (~200nm) on a glass surface, we have been able to trap individual nano-diamonds, and capture their spectral signatures. The Brownian motion in the trap can be tracked, and this leads to the measurement of effective trap stiffness. Furthermore, we extrapolate this thermo-plasmonic trapping method to trap and track individual nano-diamonds on silver nanowires.
As mentioned in the abstract of the manuscript, we envisage that our drop-casting platform can be extrapolated to perform targeted, low-power trapping, manipulation, and multimodal imaging of FNDs inside biological systems such as cells.
arxiv link to the paper : https://arxiv.org/abs/2210.02874
below is the snapshot of the abstract of the paper from journal’s early posting :
VISMAYA - History & Philosophy of Science 