Applications of trimetallic nanomaterials as Non-Enzymatic glucose sensors.

OBJECTIVE: This article critically reviews recent research on the use of trimetallic nanomaterials for the fabrication of non-enzymatic glucose sensors (NEGS), also known as fourth-generation glucose sensors (FGGS). SIGNIFICANCE: Diabetes is a prevalent chronic disease worldwide, and glucose monitoring is crucial for its management. However, conventional enzymatic glucose sensors suffer from several technological drawbacks, and there is a need to develop new-generation glucose sensors that can overcome these limitations. NEGS, particularly those composed of trimetallic nanocomposites, have demonstrated promising results in terms of improved shelf life, higher sensitivity, and simplicity of operation during glucose measurement. METHODS: In this review, we discuss the different trimetallic nanomaterials developed and used by researchers in recent years for glucose detection, including their mechanisms of action. We also provide a brief discussion of the advantages and disadvantages of FGGS-based trimetallic nanomaterials, as well as the industrial challenges in this area of research. RESULTS: Trimetallic nanomaterials for FGGS have shown excellent reproducibility and high stability, making them suitable for continuous glucose monitoring. The different types of trimetallic nanomaterials have varying sensing properties, and their performance can be tuned by controlling their synthesis parameters. CONCLUSION: Trimetallic nanomaterials are a promising avenue for the development of FGGS, recent research has demonstrated their potential for glucose monitoring. However, there are still some challenges that need to be addressed before their widespread adoption, such as their long-term stability and cost-effectiveness. Further research in this area is needed to overcome these challenges and to develop commercially viable FGGS for diabetes management.

Nanomaterials-Based Sensors for Respiratory Viral Detection: A Review.

Contagious diseases are the principal cause of mortality, particularly respiratory viruses, a real menace for public health and economic development worldwide. Therefore, timely diagnosis and treatments are the only life-saving strategy to overcome any epidemic and particularly the ongoing prevailing pandemic COVID-19 caused by SARS-CoV-2. A rapid identification, point of care, portable, highly sensitive, stable, and inexpensive device is needed which is exceptionally satisfied by sensor technology. Consequently, the researchers have directed their attention to employing sensors targeting multiple analyses of pathogenic detections across the world. Nanostructured materials (nanoparticles, nanowires, nanobundles, etc.), owing to their unique characteristics such as large surface-to-volume ratio and nanoscale interactions, are widely employed to fabricate facile sensors to meet all the immediate emerging challenges and threats. This review is anticipated to foster researchers in developing advanced nanomaterials-based sensors for the increasing number of COVID-19 cases across the globe. The mechanism of respiratory viral detection by nanomaterials-based sensors has been reported. Moreover, the advantages, disadvantages, and their comparison with conventional sensors are summarized. Furthermore, we have highlighted the challenges and future potential of these sensors for achieving efficient and rapid detection.

Nanohybrid nanozyme based colourimetric immunosensor for porcine gelatin.

Enzyme mimicking nanomaterials, nanozymes, have gained considerable interest in the scientific community because of their superior properties compared to natural enzymes, including their high stability at extreme conditions, cheaper availability, and ease of synthesis. Herein, we report novel colloidal gold nanoparticles - graphene nanoplatelets - chitosan (CS) with peroxidase mimicking properties used to carry out highly sensitive and selective immunoassay for porcine gelatin detection. The interaction between anti-gelatin antibody conjugated nanozyme with porcine gelatin proteins produced an ultrasensitive immunoassay response in the form of a colourimetric signal directly proportional to the porcine gelatin protein concentration. The nanozyme produced a colourimetric response in the presence of its substrate, 3,3',5,5'-tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2), demonstrating its peroxidase mimicking properties. The results revealed that the nanozyme exhibited remarkable selectivity and sensitivity in the assay, detecting proteins at concentrations as low as 86.42 pg/mL. Additionally, the immunosensor demonstrated a broad linear detection range spanning from 200 pg/mL to 2 ng/mL.

CeO2 nanozyme mediated RPA/CRISPR-Cas12a dual-mode biosensor for detection of invA gene in Salmonella.

This study reports a novel biosensing system that leverages recombinase polymerase amplification (RPA) in conjunction with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a technology, integrated with a nanozyme (NZ) based on cerium dioxide (CeO2). With the integration of CeO2 NZ, a dual-mode detection platform could be developed for Salmonella detection using fluorometric and colourimetric assays. The CRISPR/Cas12a system, when activated in the presence of target DNA, could cleave the FAM-labelled probe to lead to a fluorometric response. Also, when the CeO2 NZ was introduced in the presence of H2O2, a colourimetric response was generated, directly proportional to the concentration of target DNA present. We hypothesise that adding highly reactive H2O2 within the post-CRISPR/Cas12a reaction system allows for increased release of hydroxyl free radicals within the mixture. Thus, the double recognition through NZ and the CRISPR/Cas12a system provided enhanced selectivity and sensitivity to the method. The proposed biosensor could successfully detect Salmonella at concentrations as low as 0.88 pg/µL and 1.28 pg/µL for fluorometric and colourimetric responses, respectively. Furthermore, the developed biosensor could be applied in real sample analysis of raw food samples (chicken, egg, and beef) to give a good recovery in the spiked food samples with varying concentrations of cultured bacterial DNA.

Bioinspired and Green Synthesis of Silver Nanoparticles for Medical Applications: A Green Perspective.

Silver nanoparticles (AgNPs) possess unmatched chemical, biological, and physical properties that make them unique compounds as antimicrobial, antifungal, antiviral, and anticancer agents. With the increasing drug resistance, AgNPs serve as promising entities for targeted drug therapy against several bacterial, fungal, and viral components. In addition, AgNPs also serve as successful anticancer agents against several cancers, including breast, prostate, and lung cancers. Several works in recent years have been done towards the development of AgNPs by using plant extracts like flowers, leaves, bark, root, stem, and whole plant parts. The green method of AgNP synthesis thus has several advantages over chemical and physical methods, especially the low cost of synthesis, no toxic byproducts, eco-friendly production pathways, can be easily regenerated, and the bio-reducing potential of plant derived nanoparticles. Furthermore, AgNPs are biocompatible and do not harm normally functioning human or host cells. This review provides an exhaustive overview and potential of green synthesized AgNPs that can be used as antimicrobial, antifungal, antiviral, and anticancer agents. After a brief introduction, we discussed the recent studies on the development of AgNPs from different plant extracts, including leaf parts, seeds, flowers, stems, bark, root, and whole plants. In the following section, we highlighted the different therapeutic actions of AgNPs against various bacteria, fungi, viruses, and cancers, including breast, prostate, and lung cancers. We then highlighted the general mechanism of action of AgNPs. The advantages of the green synthesis method over chemical and physical methods were then discussed in the article. Finally, we concluded the review by providing future perspectives on this promising field in nanotechnology.

Non-enzymatic glucose sensors composed of trimetallic CuO/Ag/NiO based composite materials.

The escalating risk of diabetes and its consequential impact on cardiac, vascular, ocular, renal, and neural systems globally have compelled researchers to devise cost-effective, ultrasensitive, and reliable electrochemical glucose sensors for the early diagnosis of diabetes. Herein, we utilized advanced composite materials based on nanoporous CuO, CuO/Ag, and CuO/Ag/NiO for glucose detection. The crystalline structure and surface morphology of the synthesized materials were ascertained via powder X-ray diffraction (P-XRD), energy dispersive X-ray (EDX) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. The electro-catalytic properties of the manufactured electrode materials for glucose electro-oxidation in alkaline conditions were probed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. Notably, the CuO/Ag/NiO electrode material exhibited exceptional performance as a non-enzymatic glucose sensor, displaying a linear range of 0.001-5.50 mM, an ultrahigh sensitivity of 2895.3 µA mM-1 cm-2, and a low detection limit of 0.1 µM. These results suggest that nanoporous CuO/Ag/NiO-based composite materials are a promising candidate for early diagnosis of hyperglycemia and treatment of diabetes. Furthermore, non-enzymatic glucose sensors may pave the way for novel glucometer markets.

Recent Advances in Anticancer Activity of Novel Plant Extracts and Compounds from Curcuma longa in Hepatocellular Carcinoma.

PURPOSE: Among all forms of cancers, hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. There are several treatment options for HCC ranging from loco-regional therapy to surgical treatment. Yet, there is high morbidity and mortality. Recent research focus has shifted towards more effective and less toxic cancer treatment options. Curcumin, the active ingredient in the Curcuma longa plant, has gained widespread attention in recent years because of its multifunctional properties as an antioxidant, anti-inflammatory, antimicrobial, and anticancer agent. METHODS: A systematic search of PubMed, Embase and Google Scholar was performed for studies reporting incidence of HCC, risk factors associated with cirrhosis and experimental use of curcumin as an anti-cancer agent. RESULTS: This review exclusively encompasses the anti-cancer properties of curcumin in HCC globally and it's postulated molecular targets of curcumin when used against liver cancers. CONCLUSIONS: This review is concluded by presenting the current challenges and future perspectives of novel plant extracts derived from C. longa and the treatment options against cancers.

Applications of graphene-based electrochemical and optical biosensors in early detection of cancer biomarkers.

Graphene is a one-atom-thick carbon compound, which holds promises for detecting cancer biomarkers along with its derivatives. The atom-wide graphene layer is ideal for cancer biomarker detection due to its unique physicochemical properties like increased electrical and thermal conductivity, optical transparency, and enhanced chemical and mechanical strength. The scientific aim of any biosensor is to create a smaller and portable point of care device for easy and early cancer detection; graphene is able to live up to that. Apart from tumour detection, graphene-based biosensors can diagnose many diseases, their biomarkers, and pathogens. Many existing remarkable pieces of research have proven the candidacy of nanoparticles in most cancer biomarkers detection. This article discusses the effectiveness of graphene-based biosensors in different cancer biomarker detection. This article provides a detailed review of graphene and its derivatives that can be used to detect cancer biomarkers with high specificity, sensitivity, and selectivity. We have highlighted the synthesis procedures of graphene and its products and also discussed their significant properties. Furthermore, we provided a detailed overview of the recent studies on cancer biomarker detection using graphene-based biosensors. The different paths to create and modify graphene surfaces for sensory applications have also been highlighted in each section. Finally, we concluded the review by discussing the existing challenges of these biosensors and also highlighted the steps that can be taken to overcome them.

Nanozyme-based sensors for detection of food biomarkers: a review.

Nanozymes have piqued the curiosity of scientists in recent years because of their ability to demonstrate enzyme-like activity combined with advantages such as high stability, inexpensive availability, robust activity, and tunable properties. These attributes have allowed the successful application of nanozymes in sensing to detect various chemical and biological target analytes, overcoming the shortcomings of conventional detection techniques. In this review, we discuss recent developments of nanozyme-based sensors to detect biomarkers associated with food quality and safety. First, we present a brief introduction to this topic, followed by discussing the different types of sensors used in food biomarker detection. We then highlight recent studies on nanozyme-based sensors to detect food markers such as toxins, pathogens, antibiotics, growth hormones, metal ions, additives, small molecules, and drug residues. In the subsequent section, we discuss the challenges and possible solutions towards the development of nanozyme-based sensors for application in the food industry. Finally, we conclude the review by discussing future perspectives of this field towards successful detection and monitoring of food analytes.

Nanomaterials-based sensors for the detection of COVID-19: A review.

With the threat of increasing SARS-CoV-2 cases looming in front of us and no effective and safest vaccine available to curb this pandemic disease due to its sprouting variants, many countries have undergone a lockdown 2.0 or planning a lockdown 3.0. This has upstretched an unprecedented demand to develop rapid, sensitive, and highly selective diagnostic devices that can quickly detect coronavirus (COVID-19). Traditional techniques like polymerase chain reaction have proven to be time-inefficient, expensive, labor intensive, and impracticable in remote settings. This shifts the attention to alternative biosensing devices that can be successfully used to sense the COVID-19 infection and curb the spread of coronavirus cases. Among these, nanomaterial-based biosensors hold immense potential for rapid coronavirus detection because of their noninvasive and susceptible, as well as selective properties that have the potential to give real-time results at an economical cost. These diagnostic devices can be used for mass COVID-19 detection to understand the rapid progression of the infection and give better-suited therapies. This review provides an overview of existing and potential nanomaterial-based biosensors that can be used for rapid SARS-CoV-2 diagnostics. Novel biosensors employing different detection mechanisms are also highlighted in different sections of this review. Practical tools and techniques required to develop such biosensors to make them reliable and portable have also been discussed in the article. Finally, the review is concluded by presenting the current challenges and future perspectives of nanomaterial-based biosensors in SARS-CoV-2 diagnostics.

Advances in nanomaterial-based immunosensors for prostate cancer screening.

Prostate cancer is one of the most common health hazards for men worldwide, specifically in Western countries. Rapid prostate cancer screening by analyzing the prostate-specific antigen present in male serum has brought about a sharp decline in the mortality index of this disease. Immunoassay technology quantifies the target analyte in the sample using the antigen-antibody reaction. Immunoassays are now pivotal in disease diagnostics, drug monitoring, and pharmacokinetics. Recently, immunosensors have gained momentum in delivering better results with high specificity and lower limit of detection (LOD). Nanomaterials like gold, silver, and copper exhibit numerous exceptional features and their use in developing immunosensors have garnered excellent results in the diagnostic field. This review highlights the recent and different immunoassay techniques used to detect prostate-specific antigens and discusses the advances in nanomaterial-based immunosensors to detect prostate cancer efficiently. The review also explores the importance of specific biomarkers and nanomaterials-based biosensors with good selectivity and sensitivity to prostate cancer.

Fourth-generation glucose sensors composed of copper nanostructures for diabetes management: A critical review.

More than five decades have been invested in understanding glucose biosensors. Yet, this immensely versatile field has continued to gain attention from the scientific world to better understand and diagnose diabetes. However, such extensive work done to improve glucose sensing devices has still not yielded desirable results. Drawbacks like the necessity of the invasive finger-pricking step and the lack of optimization of diagnostic interventions still need to be considered to improve the testing process of diabetic patients. To upgrade the glucose-sensing devices and reduce the number of intermediary steps during glucose measurement, fourth-generation glucose sensors (FGGS) have been introduced. These sensors, made using robust electrocatalytic copper nanostructures, improve diagnostic efficiency and cost-effectiveness. This review aims to present the essential scientific progress in copper nanostructure-based FGGS in the past 10 years (2010 to present). After a short introduction, we presented the working principles of these sensors. We then highlighted the importance of copper nanostructures as advanced electrode materials to develop reliable real-time FGGS. Finally, we cover the advantages, shortcomings, and prospects for developing highly sensitive, stable, and specific FGGS.

2D materials, synthesis, characterization and toxicity: A critical review.

Nanotechnology is an arena of exploration and innovation concerned with building things generally, advancing resources and devices based on highly specific and superior nanomaterials with unmatched properties dependent on their morphology and diameter. 2D materials such as graphene have unique properties and applications varying from imaging, delivery of drugs, and theranostics of diseases. Each 2D material, ranging from the graphene family, MXenes, chalcogenides, and 2D oxides, have a unique potential based on their shape and morphology. In addition, 2D materials have intriguing physiochemical characteristics, increased aspect ratio and associated increased reactivity that make them an ideal contender in multiple applications. This review aims to answer the existing knowledge gaps in various 2D materials having interdisciplinary roles. We have presented a brief overview of the 2D materials, followed by their synthesis methods and techniques. We have also highlighted the different characterization methods used to characterise various 2D materials. Next, we performed an in-depth analysis of the potential toxicities of 2D materials to assess their risks in multiple applications. Lastly, we conclude our review by presenting the challenges and future perspectives of 2D materials as promising forerunners of science and technology.

Recent Advances in Non-Enzymatic Glucose Sensors Based on Metal and Metal Oxide Nanostructures for Diabetes Management- A Review.

There is an undeniable growing number of diabetes cases worldwide that have received widespread global attention by many pharmaceutical and clinical industries to develop better functioning glucose sensing devices. This has called for an unprecedented demand to develop highly efficient, stable, selective, and sensitive non-enzymatic glucose sensors (NEGS). Interestingly, many novel materials have shown the promising potential of directly detecting glucose in the blood and fluids. This review exclusively encompasses the electrochemical detection of glucose and its mechanism based on various metal-based materials such as cobalt (Co), nickel (Ni), zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), titanium (Ti), iridium (Ir), and rhodium (Rh). Multiple aspects of these metals and their oxides were explored vis-à-vis their performance in glucose detection. The direct glucose oxidation via metallic redox centres is explained by the chemisorption model and the incipient hydrous oxide/adatom mediator (IHOAM) model. The glucose electrooxidation reactions on the electrode surface were elucidated by equations. Furthermore, it was explored that an effective detection of glucose depends on the aspect ratio, surface morphology, active sites, structures, and catalytic activity of nanomaterials, which plays an indispensable role in designing efficient NEGS. The challenges and possible solutions for advancing NEGS have been summarized.

Thermocatalytic Hydrogen Production Through Decomposition of Methane-A Review.

Consumption of fossil fuels, especially in transport and energy-dependent sectors, has led to large greenhouse gas production. Hydrogen is an exciting energy source that can serve our energy purposes and decrease toxic waste production. Decomposition of methane yields hydrogen devoid of COx components, thereby aiding as an eco-friendly approach towards large-scale hydrogen production. This review article is focused on hydrogen production through thermocatalytic methane decomposition (TMD) for hydrogen production. The thermodynamics of this approach has been highlighted. Various methods of hydrogen production from fossil fuels and renewable resources were discussed. Methods including steam methane reforming, partial oxidation of methane, auto thermal reforming, direct biomass gasification, thermal water splitting, methane pyrolysis, aqueous reforming, and coal gasification have been reported in this article. A detailed overview of the different types of catalysts available, the reasons behind their deactivation, and their possible regeneration methods were discussed. Finally, we presented the challenges and future perspectives for hydrogen production via TMD. This review concluded that among all catalysts, nickel, ruthenium and platinum-based catalysts show the highest activity and catalytic efficiency and gave carbon-free hydrogen products during the TMD process. However, their rapid deactivation at high temperatures still needs the attention of the scientific community.

An Overview of Copper Nanoparticles: Synthesis, Characterisation and Anticancer Activity.

In this review, we summarised the different methods for copper nanoparticle synthesis, including green methods. We highlighted that the synthesis of the copper nanoparticles from green sources is preferable as they serve as stable and reducing entities. Furthermore, we critically reviewed the effectiveness of copper- based nanoparticles in oncogenic treatments emphasizing breast, lung, colorectal, and skin cancers. Finally, we have summarised the recent progress made in copper-based nanoparticles and their applications to amplify and rectify present cancer treatment options. The synthesis, characterization, stabilization, and functionalization techniques of various copper-based nanoparticles have also been highlighted in each section. In conclusion, the review provides the outlook of copper nanoparticles in cancer diagnostics and therapeutics.