Unlocking early detection of Alzheimer's disease: The emerging role of nanomaterial-based optical sensors

Chun-Hsien Chen ^a,1, Hsin-Hua Liang ^b,e,f,1, Chun-Chi Wang ^a,c,d, Yi-Ting Yang ^e, Yi-Hui Lin ^b,*, Yen-Ling Chen ^a,e,f,g,**

^a School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807378, Taiwan

^b School of Pharmacy, China Medical University, Taichung 406040, Taiwan

^c Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung 807378, Taiwan

^d Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807378, Taiwan

^e Department of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi 621301, Taiwan

^f Center for Nano Bio-Detection, National Chung Cheng University, Chiayi 621301, Taiwan

^g Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807378, Taiwan

Alzheimer's disease (AD) is a chronic and progressive neurodegenerative disorder that affects millions of individuals worldwide. Researchers have conducted numerous studies to find accurate biomarkers for early AD diagnosis and develop more effective treatments. The main pathological hallmarks of AD are amyloid beta and Tau proteins. Other biomarkers, such as DNA, RNA, and proteins, can also be helpful in early AD diagnosis. To diagnose and treat AD promptly, it is essential to accurately measure the concentration of biomarkers in the cerebrospinal fluid or blood. However, due to the low concentrations of these biomarkers in the body, highly sensitive analytical techniques are required. To date, sensors have become increasingly important due to their high sensitivity, swift detection, and adaptable manipulation features. These qualities make them an excellent substitute for conventional instruments. Nanomaterials are commonly employed in sensors to amplify signals and improve sensitivity. This review paper summarized the integration of nanomaterials in optical sensor systems, including colorimetric, fluorescent, and surfaceenhanced Raman scattering sensors for AD biomarkers detection.

Keywords: Alzheimer's disease, Biomarkers, Nanomaterials, Optical sensors