M6 - Automated Synthesis of Gold Nanostars for Biomedical Applications

In fifteen words or less, explain the significance of this contribution (Novel Aspect).: Automated, tunable Gold nanostars synthesis improves reproducibility and enhances photothermal and imaging performance for biomedicine.

Abstract Text: Automating the synthesis of gold nanostars for biomedical Applications -an undergraduate student experience- Barsha Bajgain, Connor Shook, Evan Briezendine, Alex Krol, Eric Kerschner, Pietro Strobbia
Controlling the plasmonic properties of unique nanosystems, like nanostars, enables the advanced design and fabrication of nanomaterials for biomedical applications. Manual synthesis methods, however, are often time-consuming, expensive, and susceptible to batch variability. To address these challenges, we developed an automated, low-cost fluidic system constructed via 3D printing. This system integrates programmable syringe pumps to enable precise control over the injection rates of gold seeds, gold chloride, ascorbic acid, reducing agents, and shape-directing solutions for surfactant-free synthesis of gold nanostars. Using this automated fluidic system, we explored the nanostar-design space using automated experimentation. Nanostars were synthesized under varying flow rates and relative flow rates, yielding tunable geometries that directly impact their plasmonic behavior. Spectroscopic analysis using UV-Vis-NIR, Raman spectroscopy, and thermocouple-based photothermal measurements confirmed that optimized flow dynamics produced nanostars with enhanced SERS signals and improved photothermal conversion efficiency, evidenced by precise temperature-time profiles. These results underscore the critical role of controlled synthesis parameters in tuning nanostar physicochemical properties and establish a robust, reproducible platform for producing high-performance nanostructures for use in biological imaging, diagnostics, and other biomedical applications.