LIBS for the Quantification and Detection of Gold Nanoparticles

Undergraduate #290
Discipline: Physics
Subcategory: Nanoscience

Aaleyah J. Joe - Mary Baldwin College
Co-Author(s): Komal Vig and Cleon Barnett, Alabama State University, Montgomery, AL

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Recent strides in the use of nanoparticles for biological application in living tissue have called for the need to develop a quantification method for in-situ biological analysis. Laser induced breakdown spectroscopy (LIBS) serves as a potential solution due to its advantageous properties including versatile sampling and straightforward operation. Through short laser pulses, LIBS creates a plasma on the sample surface which yields critical elemental information. In the present work, we utilize LIBS as an analytical technique for the quantification and detection of gold nanoparticles in standard solutions and incubated in Human epithelial type 2 (HEp-2) cells. To perform these experiments, we used a Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser operating at the 266 nm, 532 nm and 1064 nm excitation wavelength over a range of energies. The 267 nm (Au I) wavelength is used for the analysis of the gold nanoparticles. In this experiment, six different concentrations of Au nanoparticles (20 nm) ranging from 0.05 µg/µL to 0.001 µg/ µL were prepared and deposited onto Silicon substrates. Our results show calibration plots with r-squared values as high as .97. Regarding the cells, seven concentrations ranging from 1.50 µg/µL to 0.03 µg/µL of Au nanoparticles were incubated with the HEp-2 cells and then deposited onto the pure Silicon substrates. At this particular emission line, 267 nm, we observed r-squared values ranging from .88 to .92. Our results are promising, but further research should be conducted to examine the numerous parameters involved with obtaining results over the plasma lifetime.

Funder Acknowledgement(s): This work was supported by NSFREU (DBI-1358923) to Dr. Komal Vig (PI) and by NSFCREST (HRD1241701) to Dr. Shree S. Singh (PI).

Faculty Advisor: Komal Vig,