Application of Oracet Blue in a novel and sensitive electrochemical biosensor for the detection of microRNA

Abstract

MicroRNAs in serum/plasma, have been introduced as a novel, reliable and specific biomarkers for detection, status monitoring and population screening of a disease. Along with the molecular biology techniques, electrochemical biosensors have become the major biosensing methods for miRNA quantification. Here we have tried to develop an electrochemical biosensing system which is simple, easy to prepare, highly sensitive and selective, cost-effective and no need for sample preparation and/or amplification. We have evaluated an anthraquinone compound Oracet Blue (OB), as an intercalative electroactive label for miRNA electrochemical biosensing. The proposed electrochemical biosensor was made of a thiolated single strand capture probe (SH-modified SS-Probe) on an Au electrode (AuE). The role of OB was electrochemical signal transducing upon hybridization of the SS-Probe to the target miRNA. Under optimized conditions, target miRNAs can be detected from 50 pM to 15 nM with a detection limit of 13.5 pM. The biosensor clearly discriminated the target miRNA from a single base mismatch and non-complementary target oligonucleotides, which could guarantee a high selectivity and specificity. Moreover, the results of real sample assay of the proposed biosensor in human serum showed a good recovery percentage as well as high reproducibility which is promising its future potential use in clinical applications.

A highly sensitive miR-195 nanobiosensor for early detection of Parkinson’s disease

“…After modification of the working electrode with the EGO and GNWs, a 3.0 ml of 220.0 nM solution of thiolated SSDNA probes was placed on the electrode and kept in the humid container for 90 min to be attached on the surface of GNWs. After a mild double-distilled water wash, the modified electrode was immersed in the solution of MCH and was washed again [51]. The prepared nanobiosensor was used for quantification of the target miRNA in the solution for the required concentration.…”

“…The prepared nanobiosensor was used for quantification of the target miRNA in the solution for the required concentration. For this purpose, a 3.0 ml drop of the required concentration of target miRNA was dropped on the surface of the modified electrode and was kept isolated for 90 min and washed with the washing solution [51]. The hybridized nanobiosensor was immersed in the 0.095 mM solution of Dox for 11 min to allow the Dox molecule being intercalated in the double-strand structure.…”

Electrochemical Biosensors for Cancer Biomarkers Detection: Recent Advances and Challenges

“…Besides, their nanobiosensor exhibits excellent selectivity and reproducibility, along with the great response on the human plasma as a real sample environment. Their achievements were superior compared to their previous study which was basically based on thiolated capture probes on the gold electrode using Oracet Blue as an electroactive label which had led to the dynamic range from 50.0 pM to 15.0 nM with a detection limit of 13.5 pM In Figure , experimental steps for the study are shown…”

A novel electrochemical nanobiosensor for the ultrasensitive and specific detection of femtomolar-level gastric cancer biomarker miRNA-106a

“…For isolating the serum, the blood samples were allowed to clot in the absence of anticoagulant and simply centrifuged with recovery of supernatant. The serum samples were kept as 300 µL aliquots at −80 °C until further processing [59]. Using a Trizol-based method, total miRNA was isolated and subjected to qRT-PCR (as the gold standard method) for miR-106a detection.…”