A Highly Sensitive Urinary Exosomal miRNAs Biosensor Applied to Evaluation of Prostate Cancer Progression.

Prostate cancer is the most common cancer in the male population, carrying a significant disease burden. PSA is a widely available screening tools for this disease. Current screen-printed carbon electrode (SPCE)-based biosensors use a two-pronged probe approach to capture urinary miRNA. We were able to successfully detect specific exosomal miRNAs (exomiRs) in the urine of patients with prostate cancer, including exomiR-451 and exomiR-21, and used electrochemistry for measurement and analysis. Our results significantly reaffirmed the presence of exomiR-451 in urine and that a CV value higher than 220 nA is capable of identifying the presence of disease (p-value = 0.005). Similar results were further proven by a PAS greater than 4 (p-value = 0.001). Moreover, a higher urinary exomiR-21 was observed in the high-T3b stage; this significantly decreased following tumor removal (p-values were 0.016 and 0.907, respectively). According to analysis of the correlation with tumor metastasis, a higher exomiR-21 was associated with lymphatic metastasis (p-value 0.042), and higher exomiR-461 expression was correlated with tumor stage (p-value 0.031), demonstrating that the present exomiR biosensor can usefully predict tumor progression. In conclusion, this biosensor represents an easy-to-use, non-invasive screening tool that is both sensitive and specific. We strongly believe that this can be used in conjunction with PSA for the screening of prostate cancer.

Urinary MicroRNA Sensing Using Electrochemical Biosensor to Evaluate Colorectal Cancer Progression.

Research in cancer diagnostics has recently established its footing and significance in the biosensor sphere, emphasizing the idea of a unique probe design used as a sensor and actuator, to identify the presence of protein, DNA, RNA, or miRNA. The fluorescein isothiocyanate (FITC) probe and biotinylated probe are designed for a two-pronged approach to the detection of the urinary miR-21 and miR-141, both of which have demonstrated significance in the development and progression of colorectal cancer, a leading cause of mortality and morbidity. The remainder of the apparatus is composed of a modified screen-printed carbon electrode (SPCE), to which the probes adhere, that transduces signals via the redox reaction between H2O2 and HRP, measured with chronoamperometry and cyclic voltammetry. The precise nature of our ultra-non-invasive biosensor makes for a highly sensitive and practical cancer detector, concluded by the significance when establishing disease presence (miR-21 p-value = 0.0176, miR-141 p-value = 0.0032), disease follow-up (miR-21 p-value = 0.00154, miR141 p-value < 0.0005), and even disease severity. This article hopes to emphasize the potential of an additional clinical tool for the management of colorectal cancer.

An Effective SARS-CoV-2 Electrochemical Biosensor with Modifiable Dual Probes Using a Modified Screen-Printed Carbon Electrode.

Due to the severe acute respiratory syndrome coronavirus (SARS-CoV-2, also called coronavirus disease 2019 (COVID-19)) pandemic starting in early 2020, all social activities ceased in order to combat its high transmission rate. Since vaccination combats one aspect for halting the spread of the virus, the biosensor community has looked at another aspect of reducing the burden of the COVID-19 pandemic on society by developing biosensors that incorporate point-of-care (POC) testing and the rapid identification of those affected in order to deploy appropriate measures. In this study, we aim first to propose a screen-printed carbon electrode (SPCE)-based electrochemical biosensor that meets the ASSURED criteria (i.e., affordable, sensitive, specific, user-friendly, rapid, equipment-free, and deliverable) for POC testing, but more importantly, we describe the novelty of our biosensor's modifiability that uses custom dual probes made from target nucleic acid sequences. Additionally, regarding the sensitivity of the biosensor, the lowest sample concentration was 10 pM (p = 0.0257) without amplification, which might challenge the traditional technique of reverse transcriptase-polymerase chain reaction (RT-PCR). The purpose of this study is to develop a means of diagnostics for the current pandemic as well as to provide an established POC platform for future epidemics.

High-Sensitivity Dual-Probe Detection of Urinary miR-141 in Cancer Patients via a Modified Screen-Printed Carbon Electrode-Based Electrochemical Biosensor.

The screening and diagnosis of cancer are hallmarks of medicine in the aging population. Recently, microRNAs have shown potential for use as biomarkers, which could advance the field of diagnostics. The presence of miRNA-141 in the serum has been well described in several malignancies. However, the invasive approach used for sampling represents the major limitation for its practical application and, hence, its notable absence as a method for screening the general population. In light of this, we aimed to develop a high-sensitivity microRNA (miR) biosensor for application in the diagnosis of all miR-141-associated cancers, such as colorectal cancer (CRC) and breast cancer (BC). The novelty lies in our dual-probe design, which is reliant on the hybridization of the fluorescein isothiocyanate (FITC) targeting probe onto an existing sample of urinary miR-141 in the first step, followed by complementary binding with a biotinylated probe that has been coated on a modified screen-printed carbon electrode (SPCE). The hybridization of the probe and sensor produces signals via the catalytic reduction of H2O2 at HRP-modified SPCEs in the presence of H2O, which was measured by either cyclic voltammetry or chronoamperometry (CA) currents. In our study, the detection and expression of miR-141 in a cohort of colorectal cancer (n = 6) and breast cancer (n = 4) samples showed that its levels were significantly higher than in a healthy cohort (n = 9) (p < 0.004). Moreover, our miR sensor demonstrated high stability, reliability, and sensitivity (p < 0.0001). This work hopefully provides new information for the detection and monitoring of de novo and existing cancers.

Real-time circulating tumor cells detection via highly sensitive needle-like cytosensor-demonstrated by a blood flow simulation.

The concept of rapid detection of circulating tumor cells (CTCs) has always been the focal point of modern and future medicine. However, the dispersity and rarity of CTCs in the bloodstream makes it hard to detect metastasis. Herein, our newly designed needle-like cytosensor demonstrates that the capture and analysis of CTCs are a much less laborious process and have more potential than ever. Our aim is to detect and capture CTCs directly in the bloodstream without altering the genetic information; further benefit of current cytosensor is allows for the whole circulation of blood to run through the cytosensor, giving a much better sensitivity and chance of detecting CTCs. Our functionalized needle-like cytosensor has been modified with 3-aminopropyltriethoxysilane, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, N-hydroxysuccinimide and conjugated streptavidin to allow the binding of the biotinylated-antibody of epithelial cell adhesion molecules, which captures targeted colon cancer CTC. The capability of our needle-like cytosensor to detect CTCs spanned from 102 to 106 cells/mL. Beyond this, the needle-like cytosensor avoids the distortion of the cell information. In addition, we constructed a blood flow simulation that mimics human circulating system about 10 mL/min speed; by using cyclic voltammetry we could detect significant signals from captured cancer CTCs more than 21 cells/mL without delay; the fluorescence dye detection was further performed for data confirmation. The future of biosensors begins with this, by providing early monitoring quality care in cancer therapy.