Novel Single-Molecule Electrical Detection Method with Applications in Cancer and Covid19 Detection

Cancer is one of the most frequent causes of death globally.^[1] Blood samples, or other body fluids, can contain cancer biomarkers such as circulating free tumor nucleic acids (ctNA), which are promising for early cancer detection in liquid biopsies.^[2]^,^[3] Detecting ctNA in the blood is challenging because of the low ctNA concentration and the low frequency of mutations compared to wild-type sequences.^[2] Nanotechnology bioelectronics methods can help to address this challenge. In particular, the Scanning Tunneling Microscopic (STM)-assisted break junctions method (STM-BJ)^[4] has recently allowed the first demonstration of detection and identification of RNA from E.Coli via single-molecule conductance.^[5] This is an ideal emerging technique for liquid biopsy bioelectronics since it is extremely sensitive, specific, and non-invasive.<br/>This work focuses on characterizing ctNAs using the STM-BJ to investigate an effective method for their ultra-sensitive detection in complex samples. The study's central hypothesis is that the sequences of ctNAs can be used to detect cancers by finding their unique electronic fingerprints. We focus the study on KRAS, BRAF, and NRAS as effective cancer biomarkers in agreement with data from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA).^[6]^,^[7] We have already obtained preliminary data for wild-type and mutated RNA sequences for a few candidate cancer biomarkers (Ex: KRAS Exon 2 Wild type, G12V, and G12C mutations). We expect to understand the bioelectronics interface between genetic material and nanostructured electrodes. Our initial analysis and the results pave the way for the early detection of bioelectronics fingerprints from biomarkers through liquid biopsy using nanotechnology. The same idea can be applied to other applications such as covid detection. We conducted a comprehensive literature survey and bioinformatics analysis to identify the most appropriate candidate nucleic acid sequences for all human coronaviruses, SARS-Cov2, and other SARS-Cov2 variants such as Delta, Omicron, etc and obtained some preliminary single-molecule conductance data. This emerging method may allow beginning treatments early, potentially saving many lives from cancer and covid patients in the future. <br/>References<br/>1. Campbell PJ, Getz G, Korbel JO, <i>et al.</i> Pan-cancer analysis of whole genomes. Nature 2020;578:82–93. DOI:10.1038/s41586-020-1969-6.<br/>2. Das J, Kelley SO. High-Performance Nucleic Acid Sensors for Liquid Biopsy Applications. Angew Chemie - Int Ed 2019. DOI:10.1002/anie.201905005.<br/>3. Henry NL, Hayes DF. Cancer biomarkers. Mol Oncol 2012;6:140–6. DOI:10.1016/j.molonc.2012.01.010.<br/>4. Xu B, Tao NJ. Measurement of single-molecule resistance by repeated formation of molecular junctions. Science (80- ) 2003;301:1221–3. DOI:10.1126/science.1087481.<br/>5. Li Y, Artés JM, Demir B, <i>et al.</i> Detection and identification of genetic material via single-molecule conductance. Nat Nanotechnol 2018;13:1167–73. DOI:10.1038/s41565-018-0285-x.<br/>6. Rheinbay E, Nielsen MM, Abascal F, <i>et al.</i> Analyses of non-coding somatic drivers in 2,658 cancer whole genomes. Nature 2020;578:102–11. DOI:10.1038/s41586-020-1965-x.<br/>7. Sapio MR, Posca D, Troncone G, <i>et al.</i> Detection of BRAF mutation in thyroid papillary carcinomas by mutant allele-specific PCR amplification (MASA). Eur J Endocrinol 2006;154:341–8. DOI:10.1530/EJE.1.02072.