title: Novel and simple electrochemical biosensor monitoring attomolar levels of miRNA-155 in breast cancer.
abstract: This work, describes for the first time, a simple biosensing design to yield an ultrasensitive electrochemical biosensor for a cancer biomarker detection, miRNA-155, with linear response down to the attomolar range. MiRNA-155 was selected for being overexpressed in breast cancer. The biosensor was assembled in two stages: (1) the immobilization of the anti-miRNA-155 that was thiol modified on an Au-screen printed electrode (Au-SPE), followed by (2) blocking the areas of non-specific binding with mercaptosuccinic acid. Atomic force microscopy (AFM) and electrochemical techniques including cyclic voltammetry (CV), impedance spectroscopy (EIS) and square wave voltammetry (SWV) confirmed the surface modification of these devices and their ability to hybridize successfully and stably with miRNA-155. The final biosensor provided a sensitive detection of miRNA-155 from 10 aM to 1.0 nM with a low detection limit (LOD) of 5.7 aM in real human serum samples. Good results were obtained in terms of selectivity towards breast cancer antigen CA-15.3 and bovine serum albumin (BSA). Raw fluid extracts from cell-lines of melanoma did not affect the biosensor response (no significant change of the blank), while raw extracts from breast cancer yielded a positive signal against miRNA-155. This simple and sensitive strategy is a promising alternative for simultaneous quantitative analysis of multiple miRNA in physiological fluids for biomedical research and point-of-care (POC) diagnosis.
authors.affiliation: BioMark-CINTESIS/ISEP, School of Engineering, Polytechnic Institute of Porto, Portugal; Molecular Mechanisms of Disease Unit, Centre of Research in Health and Environment (CISA), ESTSP-IPP, Portugal.
authors.forename: Ana R
authors.initials: AR
authors.lastname: Cardoso
authors.affiliation: BioMark-CINTESIS/ISEP, School of Engineering, Polytechnic Institute of Porto, Portugal.
authors.forename: Felismina T C
authors.initials: FTC
authors.lastname: Moreira
authors.affiliation: Molecular Mechanisms of Disease Unit, Centre of Research in Health and Environment (CISA), ESTSP-IPP, Portugal; Metabolism, Nutrition and Endocrinology Unit, Integrative Cancer Programe, Instituto de Investigação e Inovação em Saúde (i3S), University of Porto, Portugal.
authors.forename: Rúben
authors.initials: R
authors.lastname: Fernandes
authors.affiliation: BioMark-CINTESIS/ISEP, School of Engineering, Polytechnic Institute of Porto, Portugal. Electronic address: goreti.sales@gmail.com.
authors.forename: M Goreti F
authors.initials: MGF
authors.lastname: Sales
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000097:blood*; D015374:Biosensing Techniques; D001943:Breast Neoplasms / Q000097:blood*; D002417:Cattle; D058266:Dielectric Spectroscopy; D055664:Electrochemical Techniques; D005260:Female; D006801:Humans; D057230:Limit of Detection; D035683:MicroRNAs / Q000097:blood*; D018625:Microscopy, Atomic Force; D009693:Nucleic Acid Hybridization; D012710:Serum Albumin, Bovine
chemical_list: D014408:Biomarkers, Tumor; C524942:MIRN155 microRNA, human; D035683:MicroRNAs; D012710:Serum Albumin, Bovine
keywords: Anti-miRNA-155; Biosensors; Breast cancer; Eletrochemistry; miRNA-155