ZnO-nanowire morphology optimization for glucose-SERS sensing

Current technology requires diabetics to undergo painful, inconvenient, and discontinuous measurement processes several times a day. Thus, more convenient ways of measuring glucose by utilizing surface enhanced Raman spectroscopy (SERS) technique can be highly desirable. To accomplish commercially viable SERS technologies for glucose detection, an optimal substrate must be designed with higher electromagnetic (EM) enhancement and better spatial uniformity, and many parameters must be taken into consideration, such as nanoparticle sizes, shapes, dielectric environment, which all affect the EM enhancement and resonance properties of the designed structures. Our straightforward two-step substrate fabrication process involves (1) the hydrothermal synthesis to create ZnO-NWs perpendicularly standing on the substrate and (2) the liquid phase deposition (LPD) to create Au NPs on ZnO-NWs. In the presentation, we will share our most updated results on NW synthesis outcomes and Raman measurements. We will discuss (1) our extensively modified synthesis process, which includes the types of chemical compounds used, time-based synthesis temperature adjustments, and acidity levels; (2) resulting NW morphologies with different NW growth rates, lengths, diameters, and branching/tapering geometries; and (3) Raman enhancement and spatial uniformity on a large scale.