posted on 2021-05-12, 13:35authored byZi-Zhu Tan, Xiao-Dan Li, Chao-Di Kong, Na Sha, Ya-Nan Hou, Kai-Hong Zhao
Microorganisms
living in animals can function as drug delivery
systems or as detectors for some diseases. Here, we developed a biosensor
constructed by the deletion of hemF and harboring ho1, chuA, and bdfp1.6
in Escherichia coli. HemF is an enzyme
involved in heme synthesis in E. coli. ChuA and HO1 can transfer extracellular heme into cells and generate
biliverdin (BV). BDFP1.6 can bind BV autocatalytically, and it emits
a far-red fluorescence signal at 667 nm. Therefore, we named this
biosensor as the far-red light for bleeding detector (FRLBD). Our
results indicated that the FRLBD was highly efficient and specific
for detecting heme or blood in vitro. Moreover, the FRLBD could be
used to detect bleeding in the zebrafish induced by aspirin, and a
convolutional neural network was an appropriate model to identify
the fluorescence features in the images.