Design of a DOPC-MoS/AuNP hybrid as an organic bed with higher amplification for miR detection in electrochemical biosensors.

The liposome-based biosensors are used for detection of nucleic acids and proteins as organic beds which are biocompatible tools for point of care tests, but their lack of sensitivity has been challenging. Therefore, designing a proper strategy is vital to increase the sensitivity of the target in diagnostic tests. In this study, for the first time, we use a combination of cationic DOPC liposome (dioleoylphosphatidylcholine) with MoS to enhance the sensitivity of liposomal sensors clearly. The electrochemical measurements are performed between potentials at - 0.4 V and + 0.4 V with 1 mM [Fe(CN)]. At first, we construct the DOPC/MoS hybrid (as a mineral/organic bed) to promote higher electrochemical behavior than DOPC liposome (as organic bed). In this research, adding AuNP can cause attachment with both the DOPC and MoS. Therefore, the electrochemical reactions are enhanced accordingly to provide more positions for attaching the probes on the AuNP. So our DOPC-MoS/AuNP hybrid can detect miR-21 with high sensitivity (LOD = 10 aM) because of attachment of miR-21 to MoS/AuNP in addition to DOPC/AuNP. This sensor has also high specificity and repeatability as a biocompatible sensor, which can be used in point of care tests and transduction instruments.