A fires novel report of exosomal electrochemical sensor for sensing micro RNAs by using multi covalent attachment p19 with high sensitivity

Nanotechnology‐based electrochemical biosensors for monitoring breast cancer biomarkers

Breast cancer is categorized as the most widespread cancer type among women globally. On-time diagnosis can decrease the mortality rate by making the right decision in the therapy procedure. These features lead to a reduction in medication time and socioeconomic burden. The current review article provides a comprehensive assessment for breast cancer diagnosis using nanomaterials and related technologies. Growing use of the nano/biotechnology domain in terms of electrochemical nanobiosensor designing was discussed in detail. In this regard, recent advances in nanomaterial applied for amplified biosensing methodologies were assessed for breast cancer diagnosis by focusing on the advantages and disadvantages of these approaches. We also monitored designing methods, advantages, and the necessity of suitable (nano) materials from a statistical standpoint. The main objective of this review is to classify the applicable biosensors based on breast cancer biomarkers. With numerous nano-sized platforms published for breast cancer diagnosis, this review tried to collect the most suitable methodologies for detecting biomarkers and certain breast cancer cell types.

Nanomaterials assisted exosomes isolation and analysis towards liquid biopsy

Exosomes has attracted tremendous research interests as they are emerging as a new paradigm of liquid biopsy. Although the concentration of exosomes in blood is relatively abundant, there still exists various vesicle-like nanoparticles, such as microvesicles, apoptotic bodies. It's an urgent need to isolate and enrich exosomes from the complex contaminants in biofluid samples. Moreover, the expressing level of exosomal biomarkers varies a lot, which make the sensitive molecular detection of exosomes in high demand. Unfortunately, the efficient isolation and sensitive molecular quantification of exosomes is still a major obstacle hindering the further development and clinical application of exosome-based liquid biopsy. Nanomaterials, with unique physiochemical properties, have been widely used in biosensing and analysis aspects, thus they are thought as powerful tools for effective purification and molecular analysis of exosomes. In this review, we summarized the most recent progresses in nanomaterials assisted exosome isolation and analysis towards liquid biopsy. On the one hand, nanomaterials can be used as capture substrates to afford large binding area and specific affinity to exosomes. Meanwhile, nanomaterials can also be served as promising signal transducers and amplifiers for molecular detection of exosomes. Furthermore, we also pointed out several potential and promising research directions in nanomaterials assisted exosome analysis. It's envisioned that this review will give the audience a complete outline of nanomaterials in exosome study, and further promote the intersection of nanotechnology and bio-analysis.

Dual electrochemical sensing of spiked virus and SARS-CoV-2 using natural bed-receptor (MV-gal1)

It has been necessary to use methods that can detect the specificity of a virus during virus screening. In this study, we use a dual platform to identify any spiked virus and specific SARS-CoV-2 antigen, sequentially. We introduce a natural bed-receptor surface as Microparticle Vesicle-Galactins1 (MV-gal1) with the ability of glycan binding to screen every spiked virus. MV are the native vesicles which may have the gal-1 receptor. Gal-1 is the one of lectin receptor which can bind to glycan. After dropping the MV-gal1 on the SCPE/GNP, the sensor is turned on due to the increased electrochemical exchange with [Fe(CN)6]-3/-4 probe. Dropping the viral particles of SARS-CoV-2 cause to turn off the sensor with covering the sugar bond (early screening). Then, with the addition of Au/Antibody-SARS-CoV-2 on the MV-gal1@SARS-CoV-2 Antigen, the sensor is turned on again due to the electrochemical amplifier of AuNP (specific detection).For the first time, our sensor has the capacity of screening of any spike virus, and the specific detection of COVID-19 (LOD: 4.57 × 102 copies/mL) by using the natural bed-receptor and a specific antibody in the point of care test.

Recent Progress in Nanomaterials Modified Electrochemical Biosensors for the Detection of MicroRNA

MicroRNAs (miRNAs) are important non-coding, single-stranded RNAs possessing crucial regulating roles in human body. Therefore, miRNAs have received extensive attention from various disciplines as the aberrant expression of miRNAs are tightly related to different types of diseases. Furthermore, the exceptional stability of miRNAs has presented them as biomarker with high specificity and sensitivity. However, small size, high sequence similarity, low abundance of miRNAs impose difficulty in their detection. Hence, it is of utmost importance to develop accurate and sensitive method for miRNA biosensing. Electrochemical biosensors have been demonstrated as promising solution for miRNA detection as they are highly sensitive, facile, and low-cost with ease of miniaturization. The incorporation of nanomaterials to electrochemical biosensor offers excellent prospects for converting biological recognition events to electronic signal for the development of biosensing platform with desired sensing properties due to their unique properties. This review introduces the signal amplification strategies employed in miRNA electrochemical biosensor and presents the feasibility of different strategies. The recent advances in nanomaterial-based electrochemical biosensor for the detection of miRNA were also discussed and summarized based on different types of miRNAs, opening new approaches in biological analysis and early disease diagnosis. Lastly, the challenges and future prospects are discussed.

Peptide Nucleic Acid-Functionalized Nanochannel Biosensor for the Highly Sensitive Detection of Tumor Exosomal MicroRNA

Compared with free miRNAs in blood, miRNAs in exosomes have higher abundance and stability. Therefore, miRNAs in exosomes can be regarded as an ideal tumor marker for early cancer diagnosis. Here, a peptide nucleic acid (PNA)-functionalized nanochannel biosensor for the ultrasensitive and specific detection of tumor exosomal miRNAs is proposed. After PNA was covalently bound to the inner surface of the nanochannels, the detection of tumor exosomal miRNAs was achieved by the charge changes on the surface of nanochannels before and after hybridization (PNA-miRNA). Due to the neutral characteristics of PNA, the efficiency of PNA-miRNA hybridization was improved by significantly reducing the background signal. This biosensor could not only specifically distinguish target miRNA-10b from single-base mismatched miRNA but also achieve a detection limit as low as 75 aM. Moreover, the biosensor was further used to detect exosomal miRNA-10b derived from pancreatic cancer cells and normal pancreatic cells. The results indicate that this biosensor could effectively distinguish pancreatic cancer tumor-derived exosomes from the normal control group, and the detection results show good consistency with those of the quantitative reverse-transcription polymerase chain reaction method. In addition, the biosensor was used to detect exosomal miRNA-10b in clinical plasma samples, and it was found that the content of exosomal miRNA-10b in cancer patients was generally higher than that of healthy individuals, proving that the method is expected to be applied for the early diagnosis of cancer.

Ultrasensitive detection of microRNA-21 by using specific interaction of antimonene with RNA as electrochemical biosensor

MicroRNA exhibits different levels of expression in cancer and can affect the transformation, metastasis, and carcinogenesis of the cancer cell. Herein, we developed a novel kind of electrochemical microRNA biosensor based on two-dimensional nanomaterial of antimonene nano-flakes (AMNFs) and carbon quantum dots (CQDs) which were used as substrating to cadmium ion (Cd²⁺) for specific detection of breast cancer-relevant biomarker-microRNA-21. Compared to graphene, the first principle energetic calculation shows that the AMNFs have completely a stronger force interaction with single strand (ssRNA), due to the antimonene has a more delocalized 5 s/5p orbital. After the addition of complementary microRNA, due to the low adsorption affinity of double-stranded RNA (dsRNA) to antimonene, the hybridized target is easy to desorb from the antimonene interface, and the oxidation peak of metal ions is significantly reduced. Results showed the microRNA-21 concentration can be detected from 100 aM to 1 nM, the limit of detection as low as 21 aM toward microRNA-21, which is 3 times lower than those of the established microRNA biosensors. The unique combination of not be attempted before existing sensing material which has special adsorption properties represents an approach to the detection of breast cancer. And it provides a promising method for early diagnosis, monitoring, and staging of breast cancer.

Point-of-care cancer diagnostic devices: From academic research to clinical translation

Early and timely diagnosis of cancer plays a decisive role in appropriate treatment and improves clinical outcomes, improving public health. Significant advances in biosensor technologies are leading to the development of point-of-care (POC) diagnostics, making the testing process faster, easier, cost-effective, and suitable for on-site measurements. Moreover, the incorporation of various nanomaterials into the sensing platforms has yielded POC testing (POCT) platforms with enhanced sensitivity, cost-effectiveness and simplified detection schemes. POC cancer diagnostic devices provide promising platforms for cancer biomarker detection as compared to conventional in vitro diagnostics, which are time-consuming and require sophisticated instrumentation, centralized laboratories, and experienced operators. Current innovative approaches in POC technologies, including biosensors, smartphone interfaces, and lab-on-a-chip (LOC) devices are expected to quickly transform the healthcare landscape. However, only a few cancer POC devices (e.g. lateral flow platforms) have been translated from research laboratories to clinical care, likely due to challenges include sampling procedures, low levels of sensitivity and specificity in clinical samples, system integration and signal readout requirements. In this review, we emphasize recent advances in POC diagnostic devices for cancer biomarker detection and discuss the critical challenges which must be surmounted to facilitate their translation into clinical settings.

Impediometric Electrochemical Sensor Based on The Inspiration of Carnation Italian Ringspot Virus Structure to Detect an Attommolar of miR

Electrochemical sensors are the tools to detect the accurate and sensitive miRs. There is the challenge to increase the power and sensitivity of the surface for the electrochemical sensor. We design a virus-like hallow structure of cuco2o4 that it holds the large amounts of p19 protein by mimicking of inherent virus (Carnation italian ringspot virus) to detect 21mir with the limit of detection (LOD = 1aM). The electrochemical measurements are performed between the potentials at -0.3 V and +0.3 V with 1 mM [Fe(CN)6] -3/-4. After dropping the cuco2o4 on the SCPE (screen carbon printed electrode), the sensor is turned on due to the high electrochemical properties. Then, p19 proteins move into the hallow structure and inhibit the exchange of electrochemical reactions between the shells and the sensor is turned off. Then, adding the duplexes of RNA/miRs cause to increase the electrochemical property of p19 due to the change of p19 conformation and the system is turned on, again. So, for the first time, a virus-like hallow structure has been used to detect the 21miR in the human serum, MCF-7, Hella cells, with high sensitivity, specificity, and reproducibility in few minutes.

Different liposome patterns to detection of acute leukemia based on electrochemical cell sensor

Leukemia is the worst type of malignancy in children which its proper diagnosis can be used in the treatment. We design the turn-off sensor by using the different electrochemical patterns of liposomes to the detection of acute lymphoblastic leukemia cells. Our design is first sandwiched by lectin liposome which increases the electrochemical exchange on the electrode. With the addition of Molt-4 cells, the bonding connection between the n-glycan and lectin can also increase the electrochemical exchange with the high detection cells. Subsequently, the addition of boronic acid liposomes decreases the resistance due to covering glycosylation bond and the sensor is turn-off. But stable and specific binding with the sialic acid causes the higher detection of Molt-4 cells. The electrochemical measurements are performed between the potentials at -0.4 V and +0.4 V with 1 mM [Fe(CN)₆] ^-3/-4. So, for the first time, we designed a cells sensor based on the different patterns of liposomes to screening the N-glycan cells, which can be used in the point of care tests with higher sensitivity.

Functionalized DNA Enables Programming Exosomes/Vesicles for Tumor Imaging and Therapy

Exosomes serve as significant information carriers that regulate important physiological and pathological processes. Herein, functionalized DNA is engineered to be a hinge that anchors quantum dots (QDs) onto the surface of exosomes, realizing a moderate and biocompatible labeling strategy. The QDs-labeled exosomes (exosome-DNA-QDs complex) can be swiftly engulfed by tumor cells, indicating that exosome-DNA-QDs can be applied as a specific agent for tumor labeling. Furthermore, the engineered artificial vesicles of M1 macrophages (M1mv) are constructed via a pneumatic liposome extruder. The results reveal that the individual M1mv can kill tumor cells and realize desirable biological treatment. To reinforce the antitumor efficacy of M1mv and the specificity of drug release, a target-triggered drug delivery system is constructed to realize a specific microRNA-responded delivery system for visual therapy of tumors. These strategies facilitate moderate labeling and functionalization of exosomes/vesicles and construct artificial drug-delivery vesicles that simultaneously possess biological treatment and chemotherapy functions, and thus have the potential to serve as a new paradigm for tumor labeling and therapy.

Rasal2 suppresses breast cancer cell proliferation modulated by secretory autophagy

Rasal2, a Ras-GTPase-activating protein (RasGAP), is a tumor suppressor in Luminal B breast cancer, frequently metastatic and recurrent. Exosomes (Exos) are small membrane vesicles secreted by various cell types, including tumor cells, recognized as vehicles for cell-to-cell communication. Our study aimed to investigate whether Rasal2 regulates breast cancer cell growth via affecting this process. In this paper, we described that Rasal2 knockout (KO) in MCF-7 cells enhanced exosomal release and increased autophagy-related proteins in exosomal fraction, while attenuated by exosome release inhibitor GW4869. Moreover, MCF-7 cells with chloroquine (CQ) treatment boosted Rasal2 KO-induced secretory autophagy. In addition, we presented that exosomes derived from KO MCF-7 cells (KO-exo) significantly promoted breast cancer cell proliferation compared to those from MCF-7 cells transfected with an empty crispr-cas9 plasmid serving as controls (sgNT-exo); however, exosomes purified from KO MCF-7 cells co-cultured with 3-methyladenine ((3-MA + KO)-exo)/CQ ((CQ + KO)-exo) dramatically inhibited/facilitated MCF-7 cell proliferation in contrast to KO-exo group, separately. In conclusion, our findings revealed a new mechanism of Rasal2 in the regulation of breast cancer cell proliferation via autophagy-exo-mediated pathway.

Electrochemical sensors and biosensors based on the use of polyaniline and its nanocomposites: a review on recent advances

Polyaniline and its composites with nanoparticles have been widely used in electrochemical sensor and biosensors due to their attractive properties and the option of tuning them by proper choice of materials. The review (with 191 references) describes the progress made in the recent years in polyaniline-based biosensors and their applications in clinical sensing, food quality control, and environmental monitoring. A first section summarizes the features of using polyaniline in biosensing systems. A subsequent section covers sensors for clinical applications (with subsections on the detection of cancer cells and bacteria, and sensing of glucose, uric acid, and cholesterol). Further sections discuss sensors for use in the food industry (such as for sulfite, phenolic compounds, acrylamide), and in environmental monitoring (mainly pesticides and heavy metal ions). A concluding section summarizes the current state, highlights some of the challenges currently compromising performance in biosensors and nanobiosensors, and discusses potential future directions. Graphical abstract Schematic presentation of electrochemical sensor and biosensors applications based on polyaniline/nanoparticles in various fields of human life including medicine, food industry, and environmental monitoring. The simultaneous use of suitable properties polyaniline and nanoparticles can provide the fabrication of sensing systems with high sensitivity, short response time, high signal/noise ratio, low detection limit, and wide linear range by improving conductivity and the large surface area for biomolecules immobilization.

Sequential or multiplex electrochemical detection of miRs based on the p19 function relative to three sandwiches of different structural hybrids on the liposomal sensor

In this work, we designed a liposomal electrochemical sensor with DOTAP-DOPE liposome, chimeric probes, p19 as a caliper molecule, and the competitor structural hybrid (just RNA) for detection of three micro-RNAs in one SPCE/GNP electrode. The sensor is stabled when the cationic spherical DOTAP-DOPE liposomes sandwich with hybrids of the different sandwiched of probes (T-M-linear, Stem) and 21-124a-221miRs. With the addition of P19, in the presence of a sandwiched competitor (T-linear/21miR), the system is stable (ON) and is shut off in the presence of structural sandwiched hydrides of M-linear+124a/Stem+221 miR due to the lack of adequate access to segments of RNA-miRs of chimeric probes. For the first time in this study, three probes were sandwiched on the separate liposome for sequential identification of 21-124a-221 or multiplex detection of miRs (221 or 124a with 21) with high specificity and sensitivity (as low as 0.1 fM). Electrochemical impedance (EIS) were performed for sensing three miRs in PBS containing 1 mM [Fe(CN)6]^-3/-4 which DOTAP-DOPE liposome acted as an enhancing intermediate layer in the electrochemical reactions. Transmission Electron Microscopy (TEM)), Atomic Force Microscopy (AFM), Dynamic Light Scattering (DLS) and Ultraviolet-Visible (UV) spectroscopic techniques are used to understand the interactions between the DOPE-DOTAP, AuNP, different probes, miRs and p19.