Pukyong National University Undergraduate Paper Selected as Cover Article in International Journal

Yoon Jiweon and Yoo Hyeyim in Electronic Engineering
Develop High-Performance 3D Surface-Enhanced Raman Spectroscopy Sensors

Pukyong National University (President Bae Sanghoon) announced that a study co-authored by Yoon Jiweon (Bachelor's-Master's Integrated Program) and Yoo Hyeyim (senior), both majoring in Electronic Engineering, was published as a cover paper (Volume 8, Issue 10) in an SCI-level international journal (IF: 5.3) this past February.

From the left, students Yoon Jiwon and Yoo Hyeim, advisor Nam Wonil, along with the journal cover, provided by National Pukyong University

In their cover paper, "Plasmonic Nanolamination for High-Performance SERS Substrates Based on Vertically Stacked 3D Multiple Nanogaps" (supervised by Professor Nam Wonil), they successfully implemented a three-dimensional vertically stacked multiple nanogap structure with excellent uniformity and reproducibility using a nanolamination process, presenting a new guideline for high-performance 3D surface-enhanced Raman spectroscopy (SERS) sensors.

SERS is a powerful next-generation spectroscopic analysis technology capable of detecting trace amounts of substances, but its practical application has been hindered by low signal reproducibility and uniformity. Conventional horizontally aligned nanogap structures have limitations in precise control below 10nm and in increasing hotspot density. To address this, the research team introduced a nanolamination technique using a metal-insulator-metal (MIM) stacked structure to form vertically oriented multiple nanogaps, thereby securing high-density, uniform hotspots.

The team maximized the SERS signal enhancement effect by selectively removing the insulating layer through wet etching, exposing the nanogap hotspots to analyte molecules. Experimental results showed that under optimal etching conditions, the SERS signal enhancement factor reached up to 1.75 × 10^8, and high uniformity was demonstrated with a relative standard deviation (RSD) of 11% over a large area exceeding 400 pixels. Furthermore, using nanoimprint lithography, they successfully fabricated a large-area substrate of 16 cm at low cost with reproducibility.

Professor Nam Wonil (Electronic Engineering, Pukyong National University) emphasized, "This research is significant in that it presents a new approach that overcomes the limitations of uniformity and reproducibility in conventional SERS substrates. The nanolaminated SERS substrate developed in this study is expected to be utilized in various practical fields such as environmental analysis, biosensors, food safety, and explosive detection."

Yoon Jiweon and Yoo Hyeyim achieved this result while working as undergraduate researchers in Professor Nam Wonil's Nanoplasmonics Laboratory at Pukyong National University. Yoon Jiweon is conducting research on environmental sensing using SERS, while Yoo Hyeyim is engaged in digital SERS research and multivariate classification of cancer cells using SERS.