The strategy of nanoparticles and the flavone chrysin to quantify miRNA-let 7a in zepto-molar level: Its application as tumor marker

MicroRNA biosensors for the detection of liver cancer

Liver cancer is one of the deadliest types worldwide and early diagnosis is highly important for successful treatment. Therefore, it is necessary to develop rapid, sensitive, simple, and inexpensive analytical tools for its detection. MicroRNAs (miRNA) represent unique biomarkers whose expression in biofluids is strongly associated with cancer in general and miR-21, -31, -122, -145, -146a, -200c, -221, -222, and -223 in liver cancer, specifically. Various biosensors for miRNA detection have been developed. These include electrochemical biosensors based on amperometric, potentiometric, conductometric and impedimetric technology. Furthermore, the use of advanced nanomaterials with enhanced chemical stability, conductivity and electrocatalytic activity have greatly increased the sensitivity and specificity of these devices. The present review focuses on recent advances in electrochemical biosensors for miRNA detection in liver cancer.

Development of a New Route for the Immobilization of Unmodified Single-Stranded DNA on Chitosan Beads and Detection of Released Guanine after Hydrolysis

In this work, chitosan beads were used as a cost-effective platform for the covalent immobilization of unmodified single-stranded DNA, using glutaraldehyde as a cross-linking agent. The immobilized DNA capture probe was hybridized in the presence of miRNA-222 as a complementary sequence. The target was evaluated based on the electrochemical response of the released guanine, using hydrochloride acid as a hydrolysis agent. Differential pulse voltammetry technique and screen-printed electrodes modified with COOH-functionalized carbon black were used to monitor the released guanine response before and after hybridization. The functionalized carbon black provided an important signal amplification of guanine compared to the other studied nanomaterials. Under optimal conditions (6 M HCl at 65 °C for 90 min), an electrochemical-based label-free genosensor assay exhibited a linear range between 1 nM and 1 µM of miRNA-222, with a detection limit of 0.2 nM of miRNA-222. The developed sensor was successfully used to quantify miRNA-222 in a human serum sample.

MicroRNA biosensors for detection of gastrointestinal cancer

Gastrointestinal (GI) cancers are one of the most common causes of cancer-related mortality. The discovery of microRNAs (miRs) and their unique role in cancer and other diseases has prompted the development of highly sensitive molecular diagnostic tools using nanomaterials as sensitive and specific biosensors. Among these, electrochemical biosensors, which are based on a simple and inexpensive design, make them desirable in clinical applications as well as a mass-produced point-of-care device. We review miR-based electrochemical biosensors in GI cancer and examine the use of nanoparticles in the evolving development of miR-based biosensors. Among these, a number of approaches including redox labeled probes, catalysts, redox intercalating agents and free redox indicators are highlighted for use in electrochemical biosensor technology.

Evolution of nucleic acids biosensors detection limit III

This review is an update of two previous ones focusing on the limit of detection of electrochemical nucleic acid biosensors allowing direct detection of nucleic acid target (miRNA, mRNA, DNA) after hybridization event. A classification founded on the nature of the electrochemical transduction pathway is established. It provides an overall picture of the detection limit evolution of the various sensor architectures developed during the last three decades and a critical report of recent strategies.

Development of electrochemical biosensors for simultaneous multiplex detection of microRNA for breast cancer screening

A highly sensitive electrochemical biosensors has been developed for the detection of multiplex micro ribonucleic acids (miRNAs) by modifying an electrode with reduced graphene oxide/poly(2-aminobenzylamine)/gold nanoparticles and adopting porous, hollow silver-gold nanoparticles as tagged labeling with metal ions. In addition, an anti-deoxyribonucleic acid (DNA)-RNA hybrid [S9.6] antibody was used to detect different hybridized capture DNAs and miRNAs that can detect multiple miRNAs simultaneously. The developed electrochemical platform exhibits high selectivity, stability, and sensitivity with a wide linear range from 1 fM to 10 nM and a low detection limit of 0.98 fM, 3.58 fM, and 0.25 fM for miRNA-155, miRNA-21, and miRNA-16, respectively. In addition, the proposed electrochemical biosensor capable for the simultaneous detection of miRNA-155, miRNA-16, and miRNA-21, which are breast cancer biomarkers, in normal human serum, can be adopted and potentially used for breast cancer screening.

Non-Coding RNA-Based Biosensors for Early Detection of Liver Cancer

Primary liver cancer is an aggressive, lethal malignancy that ranks as the fourth leading cause of cancer-related death worldwide. Its 5-year mortality rate is estimated to be more than 95%. This significant low survival rate is due to poor diagnosis, which can be referred to as the lack of sufficient and early-stage detection methods. Many liver cancer-associated non-coding RNAs (ncRNAs) have been extensively examined to serve as promising biomarkers for precise diagnostics, prognostics, and the evaluation of the therapeutic progress. For the simple, rapid, and selective ncRNA detection, various nanomaterial-enhanced biosensors have been developed based on electrochemical, optical, and electromechanical detection methods. This review presents ncRNAs as the potential biomarkers for the early-stage diagnosis of liver cancer. Moreover, a comprehensive overview of recent developments in nanobiosensors for liver cancer-related ncRNA detection is provided.

Electrochemical Biosensors for Detection of MicroRNA as a Cancer Biomarker: Pros and Cons

Cancer is the second most fatal disease in the world and an early diagnosis is important for a successful treatment. Thus, it is necessary to develop fast, sensitive, simple, and inexpensive analytical tools for cancer biomarker detection. MicroRNA (miRNA) is an RNA cancer biomarker where the expression level in body fluid is strongly correlated to cancer. Various biosensors involving the detection of miRNA for cancer diagnosis were developed. The present review offers a comprehensive overview of the recent developments in electrochemical biosensor for miRNA cancer marker detection from 2015 to 2020. The review focuses on the approaches to direct miRNA detection based on the electrochemical signal. It includes a RedOx-labeled probe with different designs, RedOx DNA-intercalating agents, various kinds of RedOx catalysts used to produce a signal response, and finally a free RedOx indicator. Furthermore, the advantages and drawbacks of these approaches are highlighted.