Details

Autor(en) / Beteiligte

• Park, Hyung Joon
• Cho, Seunghee
• Kim, Minjoon
• Jung, Yeon Sik

Titel

Carboxylic Acid-Functionalized, Graphitic Layer-Coated Three-Dimensional SERS Substrate for Label-Free Analysis of Alzheimer’s Disease Biomarkers

Ist Teil von

• Nano letters, 2020-04, Vol.20 (4), p.2576-2584

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2020

Quelle

MEDLINE

Beschreibungen/Notizen

• Surface-enhanced Raman spectroscopy (SERS)-based protein analysis is a promising alternative to existing early stage diagnoses. However, SERS research conducted thus far accompanies challenges such as nonuniformity of plasmonic nanostructures, irregular coating of analytes, and denaturation of proteins, which seriously limit the practicability of suggested approaches. Here, we introduce a carboxylic acid-functionalized and graphitic nanolayer-coated three-dimensional SERS substrate (CGSS) fabricated by sequential nanotransfer printing. The substrate consists of well-defined, uniform gold nanowire arrays for effective Raman signal enhancement and a strong protein-immobilization layer. With an enhancement factor (EF) of 5.5 × 105, on par with the highest ever reported values, the CGSS allows the detection of protein conformational changes and the determination of protein concentration via Raman measurements. Exploiting the CGSS, we successfully measured the SERS spectra of Alzheimer’s biomarkers, tau protein and amyloid β, based on which secondary structural changes were analyzed quantitatively.