Detection of mutant genes with different types of biosensor methods

Microcapsules based on biological macromolecules for intestinal health: A review

Intestinal dysfunction is becoming increasingly associated with neurological and endocrine issues, raising concerns about its impact on world health. With the introduction of several breakthrough technologies for detecting and treating intestinal illnesses, significant progress has been made in the previous few years. On the other hand, traditional intrusive diagnostic techniques are expensive and time-consuming. Furthermore, the efficacy of conventional drugs (not capsules) is reduced since they are more likely to degrade before reaching their target. In this context, microcapsules based on different types of biological macromolecules have been used to encapsulate active drugs and sensors to track intestinal ailments and address these issues. Several biomacromolecules/biomaterials (natural protein, alginate, chitosan, cellulose and RNA etc.) are widely used for make microcapsules for intestinal diseases, and can significantly improve the therapeutic effect and reduce adverse reactions. This article systematically summarizes microencapsulated based on biomacromolecules material for intestinal health control and efficacy enhancement. It also discusses the application and mechanism research of microencapsulated biomacromolecules drugs in reducing intestinal inflammation, in addition to covering the preparation techniques of microencapsulated drug delivery systems used for intestinal health. Microcapsule delivery systems' limits and potential applications for intestinal disease diagnosis, treatment, and surveillance were highlighted.

DNA/RNA-based electrochemical nanobiosensors for early detection of cancers

Nucleic acids, like DNA and RNA, serve as versatile recognition elements in electrochemical biosensors, demonstrating notable efficacy in detecting various cancer biomarkers with high sensitivity and selectivity. These biosensors offer advantages such as cost-effectiveness, rapid response, ease of operation, and minimal sample preparation. This review provides a comprehensive overview of recent developments in nucleic acid-based electrochemical biosensors for cancer diagnosis, comparing them with antibody-based counterparts. Specific examples targeting key cancer biomarkers, including prostate-specific antigen, microRNA-21, and carcinoembryonic antigen, are highlighted. The discussion delves into challenges and limitations, encompassing stability, reproducibility, interference, and standardization issues. The review suggests future research directions, exploring new nucleic acid recognition elements, innovative transducer materials and designs, novel signal amplification strategies, and integration with microfluidic devices or portable instruments. Evaluating these biosensors in clinical settings using actual samples from cancer patients or healthy donors is emphasized. These sensors are sensitive and specific at detecting non-communicable and communicable disease biomarkers. DNA and RNA's self-assembly, programmability, catalytic activity, and dynamic behavior enable adaptable sensing platforms. They can increase biosensor biocompatibility, stability, signal transduction, and amplification with nanomaterials. In conclusion, nucleic acids-based electrochemical biosensors hold significant potential to enhance cancer detection and treatment through early and accurate diagnosis.

Highly efficient, label free, ultrafast plasmonic SERS biosensor (silver nanoarrays/Si) to detect GJB2 gene expressed deafness mutations in real time validated with PCR studies

Rapid diagnostics of any gene mutations related to organ loss is highly demanded now-a days to consume time as well to reduce cost. Currently, Surface enhanced Raman spectroscopy (SERS) is evolved to be a rapid investigating tool to screen gene mutations down to single molecule sensing with regard to the design and development of substrates used for sensing. The current research focuses on particular towards direct detection of deafness mutations associated with single and dual sites related to GJB2 gene. SERS Sensor construction is achieved with plasmonic silver nanoarrays on Si (SNA/Si) substrate by effortless wet chemical methods (Reaction time: 35 s; Concentration: 20 mM). The fabricated SNA/Si facilitates direct sensing of the deafness mutations of GJB2 gene in single as well dual sites with the enhancement of plasmonic hotspots. Normal DNA DMF-33 (GGGGGG) as well as Mutant DNA at single site DMF-9 (GGGGG) were validated by their guanine fingerprint Raman bands intensity quenching for mutant DNA DMF-9 at 1366 cm-1 and 1595 cm-1 respectively. Likewise, double mutations in DMF-19 are substitutional from G to A, portrayed highly intense fingerprint of Adenine Raman bands at 739 cm-1, 1432 cm-1, 1572 cm-1 in comparison to normal DNA (DMF-33). The findings were well analyzed with Raman mapping data which carries almost 625 scans for each DNA sample. The fabricated sensor exhibited the highest sensitivity towards DNA detection down to 0.1 pg/μL with utmost reproducibility. The current study aims to bring in creation of library files for deafness mutations to facilitate clinical diagnostics in a simple and rapid approach.

Various types of electrochemical biosensors for leukemia detection and therapeutic approaches

Leukemia often initiates following dysfunctions in hematopoietic stem cells lineages. Various types of leukemia, including acute lymphoblastic leukemia (ALL), chronic myelogenous leukemia (CML), acute promyelocytic leukemia (APL), and human T-cell leukemia/lymphoma virus type 1 (HTLV-1) can thus call for different diagnosis and treatment options. One of the most important subjects in leukemia is the early detection of the disease for effective therapeutic purposes. In this respect, biosensors detecting the molecules of deoxyribonucleic acid (DNA) as analytes are called genosensors or DNA biosensors. Electrochemical sensors, as the most significant approach, also involve reacting of chemical solutions with sensors to generate electrical signals proportional to analyte concentrations. Biosensors can further help detect cancer cells in the early stages of the disease. Moreover, electrochemical biosensors, developed based on various nanomaterials (NMs), can increase sensitivity to the detection of leukemia-related genes, e.g., BCR/ABL as a fusion gene and promyelocytic leukemia/retinoic acid receptor alpha (PML/RARα). Therefore, the present review reflects on previous studies recruiting different NMs for leukemia detection.

Gas-Sensing Properties of a Carbyne-Enriched Nanocoating Deposited onto Surface Acoustic Wave Composite Substrates with Various Electrode Topologies

The application of carbyne-enriched nanomaterials opens unique possibilities for enhancing the functional properties of several nanomaterials and unlocking their full potential for practical applications in high-end devices. We studied the ethanol-vapor-sensing performance of a carbyne-enriched nanocoating deposited onto surface acoustic wave (SAW) composite substrates with various electrode topologies. The carbyne-enriched nanocoating was grown using the ion-assisted pulse-plasma deposition technique. Such carbon nanostructured metamaterials were named 2D-ordered linear-chain carbon, where they represented a two-dimensionally packed hexagonal array of carbon chains held by the van der Waals forces, with the interchain spacing approximately being between 4.8 and 5.03 Å. The main characteristics of the sensing device, such as dynamic range, linearity, sensitivity, and response and recovery times, were measured as a function of the ethanol concentration. To the authors’ knowledge, this was the first time demonstration of the detection ability of carbyne-enriched material to ethanol vapors. The results may pave the path for optimization of these sensor architectures for the precise detection of volatile organic compounds, with applications in the fields of medicine, healthcare, and air composition monitoring.

Multiplex Biosensing for Simultaneous Detection of Mutations in SARS-CoV-2

COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) has become the world's largest public health emergency of the past few decades. Thousands of mutations were identified in the SARS-CoV-2 genome. Some mutants are more infectious and may replace the original strains. Recently, B.1.1.7(Alpha), B1.351(Beta), and B.1.617.2(Delta) strains, which appear to have increased transmissibility, were detected. These strains accounting for the high proportion of newly diagnosed cases spread rapidly over the world. Particularly, the Delta variant has been reported to account for a vast majority of the infections in several countries over the last few weeks. The application of biosensors in the detection of SARS-CoV-2 is important for the control of the COVID-19 pandemic. Due to high demand for SARS-CoV-2 genotyping, it is urgent to develop reliable and efficient systems based on integrated multiple biosensor technology for rapid detection of multiple SARS-CoV-2 mutations simultaneously. This is important not only for the detection and analysis of the current but also for future mutations. Novel biosensors combined with other technologies can be used for the reliable and effective detection of SARS-CoV-2 mutants.

A Novel Fluorescence Nanobiosensor based on Modified Graphene Quantum dots-HTAB for Early Detection of Fetal Sexuality with Cell Free Fetal DNA

Recently, prenatal diagnosis with non-invasive insight is a progressive approach in clinical medicine to prevent the birth of infants with genetic abnormalities. Cell free fetal DNA (cffDNA) makes up approximately 3-6% of the bare DNA in the mother's bloodstream which is produced during pregnancy and can be used to detect fetal sex and disease in the early stages. SRY is a gene located on the chromosome Y which determines the sex of male infants. In this work, a new nanobiosensor based on the fluorescence property of r-GQD@HTAB (reduced graphene quantum dots modified with hexadecyl trimethyl ammonium bromide) was fabricated that can identify the SRY gene in cffDNA with high sensitivity and specificity. A detection limit of 0.082 nM and the linear response range of 0.16-1.5 nM was obtained for the method. It was able to discriminate the target sequence with high specificity from the non-target sequences. This biosensor includes a new graphene quantum dot modified with a surfactant, HTAB which leads to high fluorescence emission of it and then more precise differentiation between ssDNA and DsDNA in a solution. In conclusion, it provides a novel analytical tool for detection of small amount of DNA and fetal sex and genetic diseases in early stage with prenatal and noninvasive tests and applicable for clinical use.

A tailored LNA clamping design principle: Efficient, economized, specific and ultrasensitive for the detection of point mutations

In the development of personalized medicine, the ultrasensitive detection of point mutations that correlate with diseases is important to improve the efficacy of treatment and guide clinical medication. In this study, locked nucleic acid (LNA) was introduced as an amplification suppressor of a massive number of wild-type alleles in an amplification refractory mutation system (ARMS) to achieve the detection of low-abundance mutations with high specificity and sensitivity of at least 0.1%. By integrating the length of clamp, base type, number and position of LNA modifications, we have established a "shortest length with the fewest LNA bases" principle from which each LNA base would play a key role in the affinity and the ability of single base discrimination could be improve. Finally, based on this LNA design guideline, a series of the most important single point mutation sites of epidermal growth factor receptor (EGFR) was verified to achieve the optimal amplification state which as low as 0.1% mutation gene amplification was not affected under the wild gene amplification was completely inhibited, demonstrating that the proposed design principle has good applicability and versatility and is of great significance for the detection of circulating tumor DNA.

Signal amplification of novel sandwich-type genosensor via catalytic redox-recycling on platform MWCNTs/Fe3O4@TMU-21 for BRCA1 gene detection

The MWCNTs/Fe₃O₄@TMU-21 as a novel electrochemical sandwich-type genosensor was fabricated to detect the BRCA1 gene using the redox-cycling ferrocene functionalized reporter label probe (r-Fc-DNA). In the designed genosensor, the capture probe (cDNA) and r-Fc-DNA were used to detect the BRCA1 gene in sandwich-type genosensor, in which DNA sequences are well -hybridized with the BRCA1 gene (t-DNA). The cDNA was immobilized on the multiwall carbon nanotube and metal-organic framework with Fe₃O₄ nanoparticle core, which is the sensor platform. Target DNA was assayed by redox-recycling reporter probe (r-Fc-DNA) using the electro-catalytic activity of ferri/ferrocyanide, which results in significantly enhanced the oxidation peak current of r-Fc-DNA. The electrochemical redox cycling led to a high signal-to-noise ratio for gene assay. MWCNTs and Fe₃O₄@TMU-21 were applied to increase the platform conductivity and suitable binding of the recognition elements. This constructed genosensor plays an influential role in increasing the sensitivity of BRCA1 gene sequence recognition. So that under optimal conditions, this genosensor illustrated a wide linear range from 1.0×10^-15 to 1.0×10^-10 M with a detection limit of 0.57 × 10^-15 M. Moreover, the genosensor exhibited high selectivity, stability, and reproducibility. The obtained recoveries (between 91 and 105%) of the BRCA1 gene assay in human blood samples satisfactory, which can be used for BRCA1 gene measurement in the laboratory.

Advances in Electrochemical and Acoustic Aptamer-Based Biosensors and Immunosensors in Diagnostics of Leukemia

Early diagnostics of leukemia is crucial for successful therapy of this disease. Therefore, development of rapid, sensitive, and easy-to-use methods for detection of this disease is of increased interest. Biosensor technology is challenged for this purpose. This review includes a brief description of the methods used in current clinical diagnostics of leukemia and provides recent achievements in sensor technology based on immuno- and DNA aptamer-based electrochemical and acoustic biosensors. The comparative analysis of immuno- and aptamer-based sensors shows a significant advantage of DNA aptasensors over immunosensors in the detection of cancer cells. The acoustic technique is of comparable sensitivity with those based on electrochemical methods; moreover, it is label-free and provides straightforward evaluation of the signal. Several examples of sensor development are provided and discussed.

Recent advances in acoustic wave biosensors for the detection of disease-related biomarkers: A review

In the past several decades, acoustic wave biosensors, as an emerging kind of biosensors, have been developed and widely used for the detection of mass, viscosity, conductivity and density. Varieties of applications have been explored such as medical diagnosis, drug screening, environmental monitoring, food analysis and biochemical assay. Among them, the detection of disease-related biomarkers based on acoustic sensors has aroused great research interest all over the world. In this review, the classification and characteristics of acoustic wave biosensors are briefly introduced. Then, some classical studies and recent advances in disease-related biomarker detection utilizing these biosensors are summarized and detailed, respectively. Here, the disease-related biomarkers mainly include antigens, small molecular proteins, cancer cells, viruses and VOCs. Finally, challenges and future trends of these typical acoustic wave biosensors are discussed. Compared with other reviews of acoustic wave sensors, this review highlights the great potential of typical acoustic wave biosensors for early disease screening and diagnosis compared with widely-used medical imaging. Moreover, they are integrated with other technologies for the design of multi-analyte, multi-parameter and intelligent devices, collecting more comprehensive information from biomarkers. This review provides a new perspective on the applications and optimization of acoustic wave biosensors to develop more reliable platforms for disease-related biomarker detection and disease diagnosis.