Doctoral thesis

Recent studies in the human transcriptome indicate the presence of long RNA sequences in accessible human biological fluids. These sequences present a potential clinical utility as biomarkers for certain types of cancer, even though they are not translated into proteins. These transcripts, which challenge the central dogma of molecular biology are known as long noncoding RNAs, and their aberrant expression results a reliable cancer indicator. However, the monitoring of cancer-associated lncRNAs is a challenge due to their low concentration, big size, and stable secondary intermolecular structures. This PhD Thesis is intended to deal with the problem described through the development of electrochemical, ultrasensitive sensing platforms, which are also selective and based on nucleic acids as molecular receptors. The platforms will be combined with isothermal amplification of nucleic acids for the detection of colorectal cancer-associated (CRC) lncRNAs. Different lncRNAs overexpressed in CRC patients will be selected for the design of simple, low-cost analytical devices, which are expected to detect different targets in the same reaction. The integrated platforms will be evaluated for the screening and non-invasive diagnosis of CRC.