A controllable SERS biosensor for ultrasensitive detection of miRNAs based on porous MOFs and subject-object recognition ability

In this work, a simple and sensitive SERS-based miRNA biosensor was constructed based on porous MOFs nanoparticles and efficient subject-object recognition ability. MOFs as a container can package lots of signal probe neutral red (NR) for the advantages of three dimensional structure and porosity. The partially complementary duplex DNA can as a "lock" to lock up the hole for obtaining a weak Raman signal. In the present of miRNA, miRNA just like a "key" to open the duplex structure with the results of releasing NR. At this time, the released NR can be captured by SERS substrate AuNS@CB[7] for the subject-object recognition ability to produce a strong Raman signal which was positive correlation to target miRNA. By this way, the proposed SERS biosensor can achieve sensitively and selectively detect miRNA with a detection limit of 0.562 fM. This MOF-based SERS biosensor also be hopeful application for clinical diagnostics.