Paper-Based screen-printed electrode to detect miRNA-652-5p associated to Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is one of the most aggressive and lethal types of BC, affecting mostly young women and its diagnosis is difficult and requires invasive methods, such as tissue biopsy which is painful and expensive. However, nowadays liquid biopsy is emerging as a great tool for determining blood-circulating species associated to cancer and to its early diagnosis and prognosis. Among the species, the relevance of microRNAs (miRNAs) has been highlighted as promising biomarker, and miRNA-652-5p has been associated with TNBC as it promotes the growth and migration of cancer cells. In this work we designed and characterized a paper-based electrochemical device capable of recognizing and quantifying miRNA-652-5p, as future tool for liquid biopsy in TNBC. The device consists of an AuNP-modified office paper-based screen-printed electrode customized with an anti-miRNA probe for the selective recognition of miRNA-652-5p. All the experimental parameters have been carefully evaluated, and the platform allowed to detect miRNA-652-5p in standard solution and human serum down to 0.4 nM, with a satisfactory repeatability of about 6 and 3% respectively. The selectivity presence of other miRNA sequences was satisfactory demonstrated. In addition, we demonstrated the effectiveness of pre-concentration of miRNA by coupling the office paper-based electrode with an external disk made by chromatographic paper: the detection limit has been improved of 10-fold without the use of complex/expensive procedures. The presented manuscript represents an important step towards the development of a non-invasive, sensitive and TNBC-specific diagnostic platform that could improve patients' prognosis and quality of life, ulteriorly improved with pre-concentering properties of frugal supports as the external chromatographic paper-based ones.