Novel Nanochannel-Based Electrochemical miRNA Biosensors for Disease Diagnosis

Micro RNAs (miRNA) are short RNA fragments (19 – 22 nucleotides) that are tasked with the control of gene expression in several physiological processes. Recent studies have associated changes in specific miRNA concentrations in the serum with several diseases, such as cancer, pregnancy disorders, etc. Importantly, these changes are evident at early stages of the diseases, which heralds their use as potential biomarkers for early detection.
Major obstacles restricting their research and application are the extremely low miRNA concentrations in the serum and lack of adequate detection and quantification techniques. The traditional methods of cloning and Northern Blotting lack the required sensitivity, while newer and more sensitive methods such as microarray analysis and RT-PCR, are hindered by the small size of the miRNAs that complicate the analysis. Furthermore, the above methods are labour intensive and require highly specialised skills and facilities.
Hence, there is a strong need for simple and sensitive techniques for miRNA quantification. We have developed a novel electrochemical biosensing platform utilising nanoporous membranes, which exploit nanochannel blockage upon analyte binding for sensitive detection (see figure). These biosensors enable simple, sensitive and fast detection of analytes while requiring inexpensive instrumentation and facilities.
The proposed multi-disciplinary study will involve adaptation of our platform for miRNA detection and the testing of various strategies (e.g. polymer amplification) to lower detection limits. The candidate will gain knowledge and experience in working with biomolecules (DNA, PNA, miRNA, etc), nanofabrication, surface functionalisation and characterisation (SEM, FTIR, XPS), latest polymerisation technologies (eATRP) and electrochemical sensing strategies.