Exploring the Potential Applications of Engineered Borophene in Nanobiosensing and Theranostics.

A monolayer of boron known as borophene has emerged as a novel and fascinating two-dimensional (2D) material with exceptional features, such as anisotropic metallic behavior and supple mechanical and optical capabilities. The engineering of smart functionalized opto-electric 2D materials is essential to obtain biosensors or biodevices of desired performance. Borophene is one of the most emerging 2D materials, and owing to its excellent electroactive surface area, high electron transport, anisotropic behavior, controllable optical and electrochemical properties, ability to be deposited on thin films, and potential to create surface functionalities, it has recently become one of the sophisticated platforms. Despite the difficulty of production, borophene may be immobilized utilizing chemistries, be functionalized on a flexible substrate, and be controlled over electro-optical properties to create a highly sensitive biosensor system that could be used for point-of-care diagnostics. Its electrochemical properties can be tailored by using appropriate nanomaterials, redox mediators, conducting polymers, etc., which will be quite useful for the detection of biomolecules at even trace levels with a high sensitivity and less detection time. This will be quite helpful in developing biosensing devices with a very high sensitivity and with less response time. So, this review will be a crucial foundation as we have discussed the basic properties, synthesis, and potential applications of borophene in nanobiosensing, as well as therapeutic applications.

Chemically engineered unzipped multiwalled carbon nanotube and rGO nanohybrid for ultrasensitive picloram detection in rice water and soil samples.

Picloram (4-Amino-3,5,6-trichloro pyridine-2-carboxylic acid) is a chlorinated herbicide that has been discovered to be tenacious and relatively durable in both soil and water. It is known to have adverse and unpleasant effects on humans causing several health complications. Therefore, the determination of picloram is profoundly effective because of its bio-accumulative and persistent nature. Because of this, a sensitive, rapid, and robust detection system is essential to detect traces of this molecule. In this study, we have constructed a novel nanohybrid system comprising of an UZMWCNT and rGO decorated on AuNPs modified glassy carbon electrode (UZMWCNT + rGO/AuNPs/GCE). The synthesized nanomaterials and the developed system were characterized using techniques such as SEM, XRD, SWV, LSV, EIS, and chronoamperometry. The engineered sensor surface showed a broad linear range of 5 × 10-2 nM to 6 × 105 nM , a low limit of detection (LOD) of 2.31 ± 0.02 (RSD < 4.1%) pM and a limit of quantification (LOQ) of 7.63 ± 0.03 pM. The response time was recorded to be 0.2 s, and the efficacy of the proposed sensor system was studied using rice water and soil samples collected from the agricultural field post filtration. The calculated recovery % for picloram in rice water was found to be 88.58%-96.70% (RSD < 3.5%, n = 3) and for soil it was found to be 89.57%-93.24% (RSD < 3.5%, n = 3). In addition, the SWV responses of both the real samples have been performed and a linear plot have been obtained with a correlation coefficient of 0.97 and 0.96 for rice and soil samples, respectively. The interference studies due to the coexisting molecules that may be present in the samples have been found to be negligible. Also, the designed sensor has been evaluated for stability and found to be highly reproducible and stable towards picloram detection.

Nanobiosensors Design Using 2D Materials: Implementation in Infectious and Fatal Disease Diagnosis.

Nanobiosensors are devices that utilize a very small probe and any form of electrical, optical, or magnetic technology to detect and analyze a biochemical or biological process. With an increasing population today, nanobiosensors have become the broadly used electroanalytical tools for the timely detection of many infectious (dengue, hepatitis, tuberculosis, leukemia, etc.) and other fatal diseases, such as prostate cancer, breast cancer, etc., at their early stage. Compared to classical or traditional analytical methods, nanobiosensors have significant benefits, including low detection limit, high selectivity and sensitivity, shorter analysis duration, easier portability, biocompatibility, and ease of miniaturization for on-site monitoring. Very similar to biosensors, nanobiosensors can also be classified in numerous ways, either depending on biological molecules, such as enzymes, antibodies, and aptamer, or by working principles, such as optical and electrochemical. Various nanobiosensors, such as cyclic voltametric, amperometric, impedimetric, etc., have been discussed for the timely monitoring of the infectious and fatal diseases at their early stage. Nanobiosensors performance and efficiency can be enhanced by using a variety of engineered nanostructures, which include nanotubes, nanoparticles, nanopores, self-adhesive monolayers, nanowires, and nanocomposites. Here, this mini review recaps the application of two-dimensional (2D) materials, especially graphitic carbon nitride (g-C3N4), graphene oxide, black phosphorous, and MXenes, for the construction of the nanobiosensors and their application for the diagnosis of various infectious diseases at very early stage.

Engineered Biosensors for Diagnosing Multidrug Resistance in Microbial and Malignant Cells.

To curtail pathogens or tumors, antimicrobial or antineoplastic drugs have been developed. These drugs target microbial/cancer growth and survival, thereby improving the host's health. In attempts to evade the detrimental effects of such drugs, these cells have evolved several mechanisms over time. Some variants of the cells have developed resistances against multiple drugs or antimicrobial agents. Such microorganisms or cancer cells are said to exhibit multidrug resistance (MDR). The drug resistance status of a cell can be determined by analyzing several genotypic and phenotypic changes, which are brought about by significant physiological and biochemical alterations. Owing to their resilient nature, treatment and management of MDR cases in clinics is arduous and requires a meticulous approach. Currently, techniques such as plating and culturing, biopsy, gene sequencing, and magnetic resonance imaging are prevalent in clinical practices for determining drug resistance status. However, the major drawbacks of using these methods lie in their time-consuming nature and the problem of translating them into point-of-care or mass-detection tools. To overcome the shortcomings of conventional techniques, biosensors with a low detection limit have been engineered to provide quick and reliable results conveniently. These devices are highly versatile in terms of analyte range and quantities that can be detected to report drug resistance in a given sample. A brief introduction to MDR, along with a detailed insight into recent biosensor design trends and use for identifying multidrug-resistant microorganisms and tumors, is presented in this review.

Drug Encapsulated Lipid-Polymeric Nanohybrid as a Chemo-therapeutic Platform of Cancer.

The focus of this research is to design a bioengineered drug delivery vehicle that is efficient in anti-cancer drug delivery in a controlled manner. The experimental work focuses on constructing a methotrexate-loaded nano lipid polymer system (MTX-NLPHS) that can transport methotrexate (MTX) in MCF-7 cell lines in a controlled manner through endocytosis via phosphatidylcholine. In this experiment, MTX is embedded with polylactic-co-glycolic acid (PLGA) in phosphatidylcholine, which acts as a liposomal framework for regulated drug delivery. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and dynamic light scattering (DLS) were utilized to characterize the developed nanohybrid system. The particle size and encapsulation efficiency of the MTX-NLPHS were found to be 198 ± 8.44 nm and 86.48 ± 0.31 %, respectively, which is suitable for biological applications. The polydispersity index (PDI) and zeta potential of the final system were found to be 0.134 ± 0.048 and -28 ± 3.50 mV, respectively. The lower value of PDI showed the homogenous nature of the particle size, whereas higher negative zeta potential prevented the system from agglomeration. An in vitro release kinetics was conducted to see the release pattern of the system, which took 250 h for 100% drug release This kind of system may carry the drug for a long time in the circulatory system and prevent the drug discharge. Other cell culture assays such as 3-(4, 5-dimethyl thiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) and reactive oxygen species (ROS) monitoring were used to see the effect of inducers on the cellular system. MTT assay showed cell toxicity of MTX-NLPHS reduced at the lower concentration of the MTX, however, toxicity increased at the higher concentration of the MTX as compared to free MTX. ROS monitoring c revealed more scavenging of ROS using MTX-NLPHS as compared to free MTX. Confocal microscopy suggested the MTX-NLPHS induced more nuclear elongation with cell shrinkage comparatively.

Gold nanostar and graphitic carbon nitride nanocomposite for serotonin detection in biological fluids and human embryonic kidney cell microenvironment.

A nanosensor comprising of gold nanostars (Au-Nstars)-graphitic carbon nitride (g-C3N4) nanocomposite layered on a glassy carbon electrode (GCE) to detect serotonin (ST) in various body fluids has been fabricated. The nanocomposite and the sensing platform have been thoroughly characterized with UV-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive X-ray photoelectron spectroscopy (EDX), and electrochemical techniques such as cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). The designed ST detection probe has achieved a linear dynamic range (LDR) in the range 5 × 10-7 and 1 × 10-3 M with a limit of detection (LOD) of 15.1 nM (RSD < 3.3%). The ST detection capability of the fabricated sensor ranges between the normal and several abnormal pathophysiological situations. The sensor effectively detects ST in real matrices such as urine and blood serum, thus, showing its direct diagnostic applicability. Additionally, the sensor has been tested in the microenvironment of human embryonic kidney (HEK) cells to assess the possibility of ST secretion in cell lines. Interferences because of co-existing molecules have been evaluated, and the shelf-life of the fabricated sensor has been obtained as 8 weeks.

Biomass-derived carbon nanomaterials for sensor applications.

In recent years, an increasing amount of attention has been paid to utilizing dedicated waste biomass as a sustainable, cheap, and abundant fuel and material source. There is a tremendous opportunity for maximizing energy production by applying different reliable waste biomass as a renewable, affordable, and excellent resource. As a result of renewable hydrocarbons such as biomass, bioenergy is produced, green chemicals are manufactured, and carbon materials are made. Furthermore, biomass can be utilized as a source of advanced carbon materials. Carbon materials derived from biomass can also be used to support catalysts in fuel cells with polymer electrolyte membranes. For the fabrication of electrochemical sensors, porous carbonaceous materials generated from biomass are highly advised owing to their specific qualities, including regenerative nature, affordability, distinctive structure, and sustainability. The surface morphology of the sensor, especially its pore volume, surface area, and pore size affects both its electrochemical and catalytic activity. Metal nanoparticle activation, doping, and dispersion are just a few of the methods that may be used to improve the performance of sensors. To detect a variety of target analytes, such as biomolecules, metal ions, contaminants, food additives, and flavonoids, some of the key or seminal advances in the field of biomass-derived carbonaceous compounds are discussed. The materials and composites made of biomass-derived carbon will be in-depth examined, evaluated, and compared in this review. The associated technological difficulties are also discussed, and future research areas are suggested for use in practical applications. Nano carbon materials have several integrated advantages, including good electrical conductivity, structural and chemical flexibility, reduced chemical functionalization, and bulk production potential, making them viable candidates for various electrochemical processes. In the coming years, bio-carbon production from waste biomass is expected to gain rapid scientific and industrial interest because it will be used in electrochemical devices and rechargeable batteries. We emphasize the variety of waste biomass precursors that are accessible, as well as the recent developments in the manufacture of bio-carbon. Carbonaceous nanoparticles generated from biomass have shown potential for use in fuel cells, bioimaging, medicinal delivery, carbon fixation, catalysis, and gas sensors. Interestingly, this article has covered these nanomaterials' new and innovative energy conversion and storage services. Finally, the remaining difficulties, perspective views, and potential research trajectories in the area are described.

Integrated lab-on-a-chip devices: Fabrication methodologies, transduction system for sensing purposes.

Lab-on-a-chip (LOC) biosensors have recently piqued the interest of the research community as a result of its potential utility in personal healthcare and disease diagnostics. LOCs devices have been consistently developed over the last decades as merging microfluidics onto a single chip for performing many lab studies at the same time, such as biochemical and biomolecular detection. Molding, microcontact printing, micromachining, and other techniques were used in the preliminary advancement of miniature sensing platforms known as micro total analysis systems (µTAS). These time-consuming and multi-step processes were utilized to create structures on a micrometer size. As time passes, new approaches and modifications for replacing rigid substrates with flexible substrates were developed. Over the years, paper and plastic substrates have shown unique properties such as durability, flexibility, mobility, cost-effective, and simple manufacturing procedure owing to their compatibility with a wide range of printing equipment. This review discusses the different types of fabrication methods and techniques such as photolithography, soft lithography, screen printing, inkjet printing, laser micromachining, nanoimprinting for designing LOC sensing devices extensively. The types of transduction systems which includes electrochemical, optical and mechanical that play an important role in sensing devices have also been extensively described in this manuscript. Additionally, detection of numerous analytes categorized into small molecules, macromolecules and cell bodies have been comprehensively reviewed in this manuscript with illustrations and tabulated form.

Nano-Engineered Surface Comprising Metallic Dendrites for Biomolecular Analysis in Clinical Perspective.

Metallic dendrites, a class of three-dimensional nanostructured materials, have drawn a lot of interests in the recent years because of their interesting hierarchical structures and distinctive features. They are a hierarchical self-assembled array of primary, secondary, and terminal branches with a plethora of pointed ends, ridges, and edges. These features provide them with larger active surface areas. Due to their enormous active areas, the catalytic activity and conductivity of these nanostructures are higher as compared to other nanomaterials; therefore, they are increasingly used in the fabrication of sensors. This review begins with the properties and various synthetic approaches of nanodendrites. The primary goal of this review is to summarize various nanodendrites-engineered biosensors for monitoring of small molecules, macromolecules, metal ions, and cells in a wide variety of real matrices. Finally, to enlighten future research, the limitations and future potential of these newly discovered materials are discussed.

Ligand conjugated lipid-based nanocarriers for cancer theranostics.

Cancer is one of the major health-related issues affecting the population worldwide and subsequently accounts for the second-largest death. Genetic and epigenetic modifications in oncogenes or tumor suppressor genes affect the regulatory systems that lead to the initiation and progression of cancer. Conventional methods, including chemotherapy/radiotherapy/appropriate combinational therapy and surgery, are being widely used for theranostics of cancer patients. Surgery is useful in treating localized tumors, but it is ineffective in treating metastatic tumors, which spread to other organs and result in a high recurrence rate and death. Also, the therapeutic application of free drugs is related to substantial issues such as poor absorption, solubility, bioavailability, high degradation rate, short shelf-life, and low therapeutic index. Therefore, these issues can be sorted out using nano lipid-based carriers (NLBCs) as promising drug delivery carriers. Still, at most, they fail to achieve site-targeted drug delivery and detection. This can be achieved by selecting a specific ligand/antibody for its cognate receptor molecule expressed on the surface of the cancer cells. In this review, we have mainly discussed the various types of ligands used to decorate NLBCs. A list of the ligands used to design nanocarriers to target malignant cells has been extensively undertaken. The approved ligand-decorated lipid-based nanomedicines with their clinical status have been explained in tabulated form to provide a wider scope to the readers regarding ligand-coupled NLBCs.

Antibody-receptor bioengineering and its implications in designing bioelectronic devices.

Antibodies play a crucial role in the defense mechanism countering pathogens or foreign antigens in eukaryotes. Its potential as an analytical and diagnostic tool has been exploited for over a century. It forms immunocomplexes with a specific antigen, which is the basis of immunoassays and aids in developing potent biosensors. Antibody-based sensors allow for the quick and accurate detection of various analytes. Though classical antibodies have prolonged been used as bioreceptors in biosensors fabrication due to their increased fragility, they have been engineered into more stable fragments with increased exposure of their antigen-binding sites in the recent era. In biosensing, the formats constructed by antibody engineering can enhance the signal since the resistance offered by a conventional antibody is much more than these fragments. Hence, signal amplification can be observed when antibody fragments are utilized as bioreceptors instead of full-length antibodies. We present the first systematic review on engineered antibodies as bioreceptors with the description of their engineering methods. The detection of various target analytes, including small molecules, macromolecules, and cells using antibody-based biosensors, has been discussed. A comparison of the classical polyclonal, monoclonal, and engineered antibodies as bioreceptors to construct highly accurate, sensitive, and specific sensors is also discussed.

Marine biological macromolecules as matrix material for biosensor fabrication.

The ocean covers two-third of our planet and has great biological heterogeneity. Marine organisms like algae, vertebrates, invertebrates, and microbes are known to provide many natural products with biological activities as well as potential sources of biomaterials for therapeutic, biomedical, biosensors, and climate stabilization. Over the years, the field of biosensors has gained huge attention due to their extraordinary ability to provide early disease diagnosis, rapid detection of various molecules and substances along with long-term monitoring. This review aims to focus on the properties and employment of various biomaterials (carbohydrate polymers, proteins, polyacids, etc.) of marine origins such as alginate, chitin, chitosan, fucoidan, carrageenan, chondroitin sulfate, hyaluronic acid, collagen, marine pigments, marine nanoparticles, hydroxyapatite, biosilica, lectins, and marine whole cell in the design and development of biosensors. Furthermore, this review also covers the source of such marine biomaterials and their promising evolution in the fabrication of biosensors that are potent to be employed in the biomedical, environmental science, and agricultural sciences domains. The use of such fabricated biosensors harnesses the system with excellent specificity, selectivity, biocompatibility, thermal stability, and minimal cost advantages.

Ultrasensitive Aptasensors for the Detection of Viruses Based on Opto-Electrochemical Readout Systems.

Viral infections are becoming the foremost driver of morbidity, mortality and economic loss all around the world. Treatment for diseases associated to some deadly viruses are challenging tasks, due to lack of infrastructure, finance and availability of rapid, accurate and easy-to-use detection methods or devices. The emergence of biosensors has proven to be a success in the field of diagnosis to overcome the challenges associated with traditional methods. Furthermore, the incorporation of aptamers as bio-recognition elements in the design of biosensors has paved a way towards rapid, cost-effective, and specific detection devices which are insensitive to changes in the environment. In the last decade, aptamers have emerged to be suitable and efficient biorecognition elements for the detection of different kinds of analytes, such as metal ions, small and macro molecules, and even cells. The signal generation in the detection process depends on different parameters; one such parameter is whether the labelled molecule is incorporated or not for monitoring the sensing process. Based on the labelling, biosensors are classified as label or label-free; both have their significant advantages and disadvantages. Here, we have primarily reviewed the advantages for using aptamers in the transduction system of sensing devices. Furthermore, the labelled and label-free opto-electrochemical aptasensors for the detection of various kinds of viruses have been discussed. Moreover, numerous globally developed aptasensors for the sensing of different types of viruses have been illustrated and explained in tabulated form.