New Platform May Accelerate Diagnosis of Alzheimer’s Disease

The Diagnostic Challenge

Alzheimer’s disease accounts for 60–70% of dementia cases worldwide. As no curative treatment currently exists, timely diagnosis is essential. While PET and MRI scans can confirm AD, they are costly, not universally available, and often detect the disease later than would be ideal.

Fluid-based biomarker tests still lack sufficient accuracy. One of the key indicators of early AD progression is the ratio of amyloid-beta (Aβ) 42 to Aβ40 in cerebrospinal fluid or blood. However, because the concentrations of these peptides are extremely low, conventional methods such as ELISA struggle to detect them reliably and simultaneously. Multiplexed sensing platforms could provide a solution, but such technologies are rare and challenging to develop.

How the New Tool Works

The Korean research team created a multiplexed digital sensing platform based on surface-enhanced Raman scattering (SERS), which uses metallic nanoparticles to amplify Raman signals from analytes.

The researchers developed several types of gold nanoparticles shaped like sunflowers, engineered to produce strong and uniform SERS signals. These nanoparticles were conjugated with detection antibodies specific to Aβ42 or Aβ40. The biomarkers themselves were captured by immobilized capture antibodies on the sensor surface, forming a “sandwich” structure similar to ELISA —⁠ but with SERS-based signal amplification providing dramatically greater sensitivity.

The platform successfully detected Aβ42 and Aβ40 across a wide concentration range (10⁻⁸ to 10⁻¹³ g/ml). The calculated limits of detection were 8.7 × 10⁻¹⁷ g/ml for Aβ42 and 1.0 × 10⁻¹⁵ g/ml for Aβ40, approximately three orders of magnitude more sensitive than conventional ELISA.

Although clinical samples were not tested in this study, the platform demonstrated reliable performance across various sample matrices, suggesting it could accurately quantify Aβ42 and Aβ40 in clinically relevant fluids such as cerebrospinal fluid and blood plasma.

Broad Utility and Low Cost

The authors note that the technology could eventually allow simultaneous quantification of AD biomarkers in clinical samples and enable early detection of changes in the Aβ42/Aβ40 ratio —⁠ a key indicator of AD risk. They also anticipate its applicability to many other diseases in which concurrent measurement of multiple biomarkers is essential.

A key advantage is its low manufacturing cost, which supports scalable production and easy adaptation to different biomarkers. Thanks to its versatility and high sensitivity, the platform could be employed in oncology, neurology, or infectious disease diagnostics, where rapid and accurate *in vitro* analysis is crucial.

Editorial Team, Medscope.pro

Sources:
1. Shim J. E., Kim Y. J., Hahm E. et al. *Ultrasensitive SERS nanoprobe-based multiplexed digital sensing platform for the simultaneous quantification of Alzheimer’s disease biomarkers.* Biosens Bioelectron. 2025;274 : 117216. doi:10.1016/j.bios.2025.117216.
2. *A new era in Alzheimer’s detection: KRISS’s ultrasensitive diagnostic platform.* Korea Research Institute of Standards and Science. 14 Aug 2025. Available at: www.kriss.re.kr