Yong Woong Jun^†# , Seo Won Cho^†#, Junyang Jung^‡, Youngbuhm Huh^‡, YoungSoo Kim^*§ , Dokyoung Kim^*‡∥⊥, and Kyo Han Ahn<sup>*†

†</sup> Department of Chemistry, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Republic of Korea
^‡Department of Anatomy and Neurobiology, College of Medicine, ^∥Center for Converging Humanities, and ^⊥Biomedical Science Institute, Kyung Hee University, 26 Kyungheedae-Ro, Dongdaemun-Gu, Seoul 02447, Republic of Korea
^§ Integrated Science and Engineering Division, Department of Pharmacy, and Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea

^*Corresponding Authors

Author Contributions
^#Y.W.J. and S.W.C. contributed equally to this work.

Alzheimer’s disease (AD) is the most common form of dementia. The pathogenesis of the disease is associated with aggregated amyloid-β, hyperphosphorylated tau, a high level of metal ions, abnormal enzyme activities, and reactive astrocytes. This outlook gives an overview of fluorescent small molecules targeting AD biomarkers for ex vivo and in vivo imaging. These chemical imaging probes are categorized based on the potential biomarkers, and their pros and cons are discussed. Guidelines for designing new sensing strategies as well as the desirable properties to be pursued for AD fluorescence imaging are also provided.