Ultrasensitive detection of multiple Alzheimer's disease biomarkers by SERS-LFA

Alzheimer's disease (AD) is one of the top public health crises in the 21st century, especially in an aging society. Early diagnosis, prevention, and intervention can significantly reduce the risk of AD. Detection of multiple AD biomarkers in blood is an effective strategy and has drawn more and more attention in recent years. However, the concentration of AD biomarkers is very low, therefore, point-of-care testing (POCT) techniques are needed for sensitive detection. Herein, a lateral flow assay, based on Surface-enhanced Raman scattering nanotags (SERS-LFA), is proposed for the simultaneous quantification of multiple AD biomarkers including Amyloid-beta 42, Amyloid-beta 40, tau proteins, and neurofilament light chain. The limit of detection for four AD biomarkers is 138.1, 191.2, 257.1, and 309.1 fg mL^-1, respectively, which are two orders of magnitude lower than their concentrations in blood. Compared with the existing detection technology, SERS-LFA has the advantages of high specificity, high sensitivity, low cost, multiple detection, and rapid detection. Therefore, SERS-LFA has a broad application prospect in the early diagnosis and monitoring of AD in the future.