[en] In vivo PET and SPECT imaging of β-amyloid (Aβ) plagues in the brain may lead to early detection of Alzheimer's Disease (AD), but the Aβ-detector labeled by ⁹⁹Tc^m fell behind. The purpose of this study was to develop novel ⁹⁹Tc^m (CO)₃⁺ -labeled β-amyloid-detector based on the flavones. Isostructural Re/⁹⁹Tc^m (CO)₃⁺ -flavones were designed and synthesized, and Re(CO)₃⁺ -flavone were studied on its binding characteristic with β- amyloid plaques in vitro by fluorescence. The results showed that the binding affinity (K_d = 5. 43 nmol/L) of Re(CO)₃⁺ -flavone was higher than flavone derivatives labeled by radioiodine. The biodistribution of normal mice showed that ⁹⁹Tc^m (CO)₃⁺ -flavone displayed moderate uptake (0.46±0.23% ID/g) at 2 min postinjection) in the brain and rapid clearance (0.13±0.04% ID/g) after 120 min injection. The above results demonstrated that ⁹⁹Tc^m (CO)₃⁺ -flavone should be desirable as a potential SPECT imaging agent for β-amyloid aggregates. (authors)