Evaluating glioma-associated microRNA by complementation on a biological nanosensor.

Glioma is a tumor in the brain and spinal cord originating in the glial cells that surround the nerve cells. Among several microRNAs reported, miRNA-363 is associated with human glioma. Based on miRNA-363 levels, the development and progression of glioma can be monitored. The current study used an interdigitated electrode sensor to monitor microRNA-363 levels, which indeed reflects the severity of glioma. The interdigitated electrode was generated using a photolithography technique followed by surface chemical modification carried out to insert miRNA-363 complementary oligo as the probe complexed with gold nanoparticles. The proposed sensor works based on the dipole moment between two electrodes, and when molecular immobilization or interaction occurs, the response by the signal output changes. The changes in the target microRNA-363 sequence were standardized to identify glioma. The limit of detection of miRNA-363 was 10 fM with an R value of 0.996 on the linear coefficient regression ranges between 1 fM and 100 pM. Furthermore, unrelated sequences failed to increase the response of the current with the complementary probe, indicating specific miRNA-363 detection on the interdigitated electrode. This study demonstrates the platform to be used for determining the presence of microRNA-363 in glioma and as the basis for other biomarker analyses.