Preparation of Living Material with Metal–Organic Frameworks and Bacteria for the Design of Electrochemical Biosensor to Detect Exosomes

As a new generation of intelligent materials, living materials composed of biological elements and non-living matrix may integrate the characteristics of both, so they have received more and more attention. However, their application to biosensor development is insufficient, especially the living materials prepared with bacteria and metal-organic frameworks (MOFs). Herein, an electroactive bacterium (Shewanella oneidensis MR-1, S.oneidensis) and one kind of MOFs (Cu-TCPP) are adopted in this work to prepare an electroactive living material, which is further used to design and fabricate an electrochemical biosensor. It is found that the integration of Cu-TCPP with S.O. can facilitate electrochemical signal output, which may be attributed to synergy effects between S.O. and Cu-TCPP. Furthermore, the living material is explored to bind with aptamers for the electrochemical detection of targets. Taking the analysis of exosomes as an example, the fabricated biosensor can detect exosomes in the range of 1.38 × 10³-1.38 × 10⁷ particles mL^-1, with the detection limit of 659 particles mL^-1, without the requirement of a signal amplification strategy, thus proposing a way of living material-based biosensor fabrication.