The invention belongs to the field of specific
molecular recognition materials and discloses a
cyanine fluorescent compound as well as a preparation method and application thereof. The structural general formula of the
cyanine fluorescent compound is shown as a formula (I). The fluorescent compound disclosed by the invention adopts a classic
cyanine dye structure, an electroneutral
electron-drawing group is introduced into the R-group position, a conjugated structure of push-pull
electron interaction is formed between the
electron-donating group and the electron-drawing group in the structure,and the
conjugated system for transition is increased by carbon-carbon double bonds, so that
fluorescence produced by compound molecules moves to a near
infrared region. Meanwhile, due to the introduced electroneutral group, the problem that most of the charged cyanine compounds cannot pass through the
blood brain barrier is solved. The compound molecule has affinity to Abeta plaques, can be successfully applied to
near infrared fluorescence imaging of the Abeta plaques, and has the advantages of being safe, non-radioactive, low in cost, low in
background fluorescence interference, high in penetrating power in biological tissues and the like. The
structural formula is as shown in the specification.