Novel and simple electrochemical biosensor monitoring attomolar levels of miRNA-155 in breast cancer

• Published in: Biosensors & bioelectronics 2016-06, Vol.80, p.621-630
• Main Authors: Cardoso, Ana R., Moreira, Felismina T.C., Fernandes, Rúben, Sales, M. Goreti F.
• Format: Article
• Language: English
• Subjects: Animals; Anti-miRNA-155; antigens; atomic force microscopy; biomarkers; Biomarkers, Tumor - blood; biomedical research; Biosensing Techniques; Biosensors; blood serum; bovine serum albumin; Breast; Breast cancer; breast neoplasms; Breast Neoplasms - blood; Cancer; Cattle; detection limit; Dielectric Spectroscopy; Electrochemical Techniques; electrochemistry; electrodes; Eletrochemistry; Female; Fluid dynamics; Fluid flow; Fluids; Humans; Limit of Detection; melanoma; microRNA; MicroRNAs - blood; Microscopy, Atomic Force; miRNA-155; monitoring; Nucleic Acid Hybridization; quantitative analysis; Raw; Serum Albumin, Bovine; thiols; Voltammetry
• ISSN: 0956-5663; 1873-4235; 1873-4235
• DOI: 10.1016/j.bios.2016.02.035

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 10aM to 1.0nM 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. •Novel simple design for preparing a miRNA biosensor on screen printed electrodes.•Complementary miRNA with adenine spacer acting as probe.•Sensitive to miRNA down to the attomolar level.•Suitable electrochemical response in human serum and cell extracts.•Of interest to screen miRNA-155 in breast cancer.