Engineered two-dimensional nanomaterials based diagnostics integrated with internet of medical things (IoMT) for COVID-19.

More than four years have passed since an inimitable coronavirus disease (COVID-19) pandemic hit the globe in 2019 after an uncontrolled transmission of the severe acute respiratory syndrome (SARS-CoV-2) infection. The occurrence of this highly contagious respiratory infectious disease led to chaos and mortality all over the world. The peak paradigm shift of the researchers was inclined towards the accurate and rapid detection of diseases. Since 2019, there has been a boost in the diagnostics of COVID-19 via numerous conventional diagnostic tools like RT-PCR, ELISA, etc., and advanced biosensing kits like LFIA, etc. For the same reason, the use of nanotechnology and two-dimensional nanomaterials (2DNMs) has aided in the fabrication of efficient diagnostic tools to combat COVID-19. This article discusses the engineering techniques utilized for fabricating chemically active E2DNMs that are exceptionally thin and irregular. The techniques encompass the introduction of heteroatoms, intercalation of ions, and the design of strain and defects. E2DNMs possess unique characteristics, including a substantial surface area and controllable electrical, optical, and bioactive properties. These characteristics enable the development of sophisticated diagnostic platforms for real-time biosensors with exceptional sensitivity in detecting SARS-CoV-2. Integrating the Internet of Medical Things (IoMT) with these E2DNMs-based advanced diagnostics has led to the development of portable, real-time, scalable, more accurate, and cost-effective SARS-CoV-2 diagnostic platforms. These diagnostic platforms have the potential to revolutionize SARS-CoV-2 diagnosis by making it faster, easier, and more accessible to people worldwide, thus making them ideal for resource-limited settings. These advanced IoMT diagnostic platforms may help with combating SARS-CoV-2 as well as tracking and predicting the spread of future pandemics, ultimately saving lives and mitigating their impact on global health systems.

Internet-of-medical-things integrated point-of-care biosensing devices for infectious diseases: Toward better preparedness for futuristic pandemics.

Microbial pathogens have threatened the world due to their pathogenicity and ability to spread in communities. The conventional laboratory-based diagnostics of microbes such as bacteria and viruses need bulky expensive experimental instruments and skilled personnel which limits their usage in resource-limited settings. The biosensors-based point-of-care (POC) diagnostics have shown huge potential to detect microbial pathogens in a faster, cost-effective, and user-friendly manner. The use of various transducers such as electrochemical and optical along with microfluidic integrated biosensors further enhances the sensitivity and selectivity of detection. Additionally, microfluidic-based biosensors offer the advantages of multiplexed detection of analyte and the ability to deal with nanoliters volume of fluid in an integrated portable platform. In the present review, we discussed the design and fabrication of POCT devices for the detection of microbial pathogens which include bacteria, viruses, fungi, and parasites. The electrochemical techniques and current advances in this field in terms of integrated electrochemical platforms that include mainly microfluidic- based approaches and smartphone and Internet-of-things (IoT) and Internet-of-Medical-Things (IoMT) integrated systems have been highlighted. Further, the availability of commercial biosensors for the detection of microbial pathogens will be briefed. In the end, the challenges while fabrication of POC biosensors and expected future advances in the field of biosensing have been discussed. The integrated biosensor-based platforms with the IoT/IoMT usually collect the data to track the community spread of infectious diseases which would be beneficial in terms of better preparedness for current and futuristic pandemics and is expected to prevent social and economic losses.

Polydopamine decorated MoS2 nanosheet based electrochemical immunosensor for sensitive detection of SARS-CoV-2 nucleocapsid protein in clinical samples.

The outbreak of the highly contagious disease COVID-19, which is triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), demands a rapid, low-cost, and highly sensitive immunosensor that can detect and identify the virus efficiently. Here, an electrochemical immunosensor based on a nanocomposite consisting of molybdenum disulfide nanosheets decorated with polydopamine (MoS2-PDA) is developed for highly sensitive detection of SARS-CoV-2 nucleocapsid protein (N protein). The MoS2-PDA nanocomposite possesses various hydroxyl and amine groups that have excellent chemistry with crosslinkers and act as adhesive agents to bind with the working electrode surface. Furthermore, the optical, functional, structural, vibrational, and morphological properties of the MoS2-PDA nanocomposite are studied using various characterization techniques such as UV-vis, FTIR, and Raman spectroscopies, XRD, and TEM. The electrochemical immunosensor is fabricated by functionalizing the MoS2-PDA nanocomposite with anti-SARS-CoV-2 nucleocapsid IgG antibody (Ab) and has a very high sensitivity against the N protein with a linear range between 10 ag mL-1 and 100 ng mL-1. The electrochemical immunosensor exhibits a lowest limit of detection (LOD) of 2.80 ag mL-1 and a limit of quantification (LOQ) of 8.48 ag mL-1via electrochemical impedance spectroscopy (EIS). Furthermore, the electrochemical immunosensor is successfully employed to detect the N protein in nasopharyngeal swab specimens and displays good consistency with the conventional RT-PCR test results. The results show that the MoS2-PDA nanocomposite-based electrochemical platform can serve as a highly sensitive and selective detector of N protein and will pave the way for the development of a point-of-care (POC) electrochemical immunosensor for rapid detection of other infectious viruses.

MXene-modified molecularly imprinted polymers as an artificial bio-recognition platform for efficient electrochemical sensing: progress and perspectives.

The development of efficient electrochemical sensors of exceptional features, molecularly imprinted polymers (MIPs), has been extensively utilized due to their great vitality as an alternative to bio-recognition elements. MIPs as an artificial bio-recognition element are getting significant attention due to their affordability, easy processability, and scaling-up capabilities. However, the challenge of longer stability and higher sensitivity associated with MIP-based sensing technology is still a remaining challenge. This can be addressed by modifying MIPs with electro-active nano-systems. Correspondingly, MXene is an emerging material of choice to make MIP-based sensing platforms more efficient and develop a bio-active-free sensing system. This review highlights state-of-the-art MXene-modified MIP electrochemical sensing platforms to overcome the associated limitations of pristine MIPs. As a proof-of-concept, the sensitive and selective detection of markers for health monitoring can be efficiently fulfilled by the high-performance MXene-MIP nanocomposite-based electrochemical sensor. Moreover, the challenges associated with this research area along with the potential solutions are also discussed. An attempt has been made to explore MXene-MIP nanocomposites as a next-generation sensing platform suitable for point-of-care testing (POCT) applications.

Next-Generation Intelligent MXene-Based Electrochemical Aptasensors for Point-of-Care Cancer Diagnostics.

Delayed diagnosis of cancer using conventional diagnostic modalities needs to be addressed to reduce the mortality rate of cancer. Recently, 2D nanomaterial-enabled advanced biosensors have shown potential towards the early diagnosis of cancer. The high surface area, surface functional groups availability, and excellent electrical conductivity of MXene make it the 2D material of choice for the fabrication of advanced electrochemical biosensors for disease diagnostics. MXene-enabled electrochemical aptasensors have shown great promise for the detection of cancer biomarkers with a femtomolar limit of detection. Additionally, the stability, ease of synthesis, good reproducibility, and high specificity offered by MXene-enabled aptasensors hold promise to be the mainstream diagnostic approach. In this review, the design and fabrication of MXene-based electrochemical aptasensors for the detection of cancer biomarkers have been discussed. Besides, various synthetic processes and useful properties of MXenes which can be tuned and optimized easily and efficiently to fabricate sensitive biosensors have been elucidated. Further, futuristic sensing applications along with challenges will be deliberated herein.

Borophene as an emerging 2D flatland for biomedical applications: current challenges and future prospects.

Recently, two-dimensional (2D)-borophene has emerged as a remarkable translational nanomaterial substituting its predecessors in the field of biomedical sensors, diagnostic tools, high-performance healthcare devices, super-capacitors, and energy storage devices. Borophene justifies its demand due to high-performance and controlled optical, electrical, mechanical, thermal, and magnetic properties as compared with other 2D-nanomaterials. However, continuous efforts are being made to translate theoretical and experimental knowledge into pragmatic platforms. To cover the associated knowledge gap, this review explores the computational and experimental chemistry needed to optimize borophene with desired properties. High electrical conductivity due to destabilization of the highest occupied molecular orbital (HOMO), nano-engineering at the monolayer level, chemistry-oriented biocompatibility, and photo-induced features project borophene for biosensing, bioimaging, cancer treatment, and theragnostic applications. Besides, the polymorphs of borophene have been useful to develop specific bonding for DNA sequencing and high-performance medical equipment. In this review, an overall critical and careful discussion of systematic advancements in borophene-based futuristic biomedical applications including artificial intelligence (AI), Internet-of-Things (IoT), and Internet-of-Medical Things (IoMT) assisted smart devices in healthcare to develop high-performance biomedical systems along with challenges and prospects is extensively addressed. Consequently, this review will serve as a key supportive platform as it explores borophene for next-generation biomedical applications. Finally, we have proposed the potential use of borophene in healthcare management strategies.

SERS Based Lateral Flow Immunoassay for Point-of-Care Detection of SARS-CoV-2 in Clinical Samples.

The current scenario, an ongoing pandemic of COVID-19, places a dreadful burden on the healthcare system worldwide. Subsequently, there is a need for a rapid, user-friendly, and inexpensive on-site monitoring system for diagnosis. The early and rapid diagnosis of SARS-CoV-2 plays an important role in combating the outbreak. Although conventional methods such as PCR, RT-PCR, and ELISA, etc., offer a gold-standard solution to manage the pandemic, they cannot be implemented as a point-of-care (POC) testing arrangement. Moreover, surface-enhanced Raman spectroscopy (SERS) having a high enhancement factor provides quantitative results with high specificity, sensitivity, and multiplex detection ability but lacks in POC setup. In contrast, POC devices such as lateral flow immunoassay (LFIA) offer rapid, simple-to-use, cost-effective, reliable platform. However, LFIA has limitations in quantitative and sensitive analyses of SARS-CoV-2 detection. To resolve these concerns, herein we discuss a unique modality that is an integration of SERS with LFIA for quantitative analyses of SARS-CoV-2. The miniaturization ability of SERS-based devices makes them promising in biosensor application and has the potential to make a better alternative of conventional diagnostic methods. This review also demonstrates the commercially available and FDA/ICMR approved LFIA kits for on-site diagnosis of SARS-CoV-2.

Biosensor-based diagnostic approaches for various cellular biomarkers of breast cancer: A comprehensive review.

Breast cancer is the most commonly occurring cancer among women which leads to thousands of deaths worldwide. The chances of survival are more if the breast cancer is diagnosed at early stage. At present, mammography, magnetic resonance imaging, ultrasound and tissue biopsies are the main diagnostic techniques available for the detection of breast cancer. However, despite of offering promising results, requirement of expensive setup, skilled supervision, expert analysis, invasive procedure (biopsy) and low capacity of multiplexing are the main limitations of these diagnostic techniques. Due to high cost, these screening tests are out of reach of people belonging to low socioeconomic groups and this poses serious health burden to the society. Recently, biosensor-based diagnostic technology for early detection of various types of cancers and other non-oncological disorders have gained considerable attention because of their several advantageous features over existing diagnostic technologies such as high throughput, noninvasive nature, cost effectiveness, easy interpretable results and capacity for multiplexing. Further, biosensors can be designed for biomarkers which are confined to particular type of cancer. In this review, we have discussed about various genomic, transcriptomic, proteomic and metabolomic biomarkers associated with breast cancer, various biosensors-based diagnostic approaches designed for detection of specific biomarkers associated with breast cancer are also described. Further, this review throws insight on various biomarkers linked with breast cancer which can be effectively exploited to develop new diagnostic technology. The assessment of these biomarkers associated with BC using biosensors in large population are cost-effective, non-invasive and high throughput. They help in risk assessment of disease at very initial stage even in backward areas and also help to lower the disease burden of society and economic cost of treatment for a common man. This review would provide new avenues for the development of biosensor based diagnostic technology for the detection of biomarkers associated with breast cancer.

Point-of-Care Biosensor-Based Diagnosis of COVID-19 Holds Promise to Combat Current and Future Pandemics.

Efficient and rapid detection of viruses plays an extremely important role in disease prevention, diagnosis, and environmental monitoring. Early screening of viral infection among the population has the potential to combat the spread of infection. However, the traditional methods of virus detection being used currently, such as plate culturing and quantitative RT-PCR, give promising results, but they are time-consuming and require expert analysis and costly equipment and reagents; therefore, they are not affordable by people in low socio-economic groups in developing countries. Further, mass or bulk testing chosen by many governments to tackle the pandemic situation has led to severe shortages of testing kits and reagents and hence are affecting the demand and supply chain drastically. We tried to include all the reported current scenario-based biosensors such as electrochemical, optical, and microfluidics, which have the potential to replace mainstream diagnostic methods and therefore could pave the way to combat COVID-19. Apart from this, we have also provided information on commercially available biosensors for detection of SARS-CoV-2 along with the challenges in development of better diagnostic approaches. It is therefore expected that the content of this review will help researchers to design and develop more sensitive advanced commercial biosensor devices for early diagnosis of viral infection, which can open up avenues for better and more specific therapeutic outcomes.

Highly Luminescent Dual Mode Polymeric Nanofiber-Based Flexible Mat for White Security Paper and Encrypted Nanotaggant Applications.

Increasing counterfeiting of important data, currency, stamp papers, branded products etc., has become a major security threat which could lead to serious damage to the global economy. Consequences of such damage are compelling for researchers to develop new high-end security features to address full-proof solutions. Herein, we report a dual mode flexible highly luminescent white security paper and nanotaggants composed of nanophosphors incorporated in polymer matrix to form a nanofiber-based mat for anti-counterfeiting applications. The dual mode nanofibers are fabricated by electrospinning technique by admixing the composite of NaYF4 :Eu3+ @NaYF4 :Yb3+ , Er3+ nanophosphors in the polyvinyl alcohol solution. This flexible polymer mat derived from nanofibers appears white in daylight, while emitting strong red (NaYF4 :Eu3+ ) and green (NaYF4 :Yb3+ , Er3+ ) colors at excitation wavelengths of 254 nm and 980 nm, respectively. These luminescent nanofibers can also be encrypted as a new class of nanotaggants to protect confidential documents. These obtained results suggest that highly luminescent dual mode polymeric nanofiber-based flexible white security paper and nanotaggants could offer next-generation high-end unique security features against counterfeiting.

Stability, Scale-up, and Performance of Quantum Dot Solar Cells with Carbonate-Treated Titanium Oxide Films.

A novel yet simple approach of carbonate (CBN) treatment of TiO2 films is performed, and quantum dot solar cells (QDSCs) with high power conversion efficiencies (PCEs), reasonably good stabilities, and good fill factors (FFs) are fabricated with TiO2-CBN films. The ability of carbonate groups to passivate defects or oxygen vacancies of TiO2 is confirmed from a nominally enhanced band gap, a lowered defect induced fluorescence intensity, an additional Ti-OH signal obtained after carbonate decomposition, and a more capacitive low frequency electrochemical impedance behavior achieved for TiO2-CBN compared to untreated TiO2. A large area QDSC of 1 cm2 with a TiO2-CBN/CdS/Au@PAA (poly(acrylic acid)) photoanode delivers an enhanced PCE of 4.32% as opposed to 3.03% achieved for its analogous cell with untreated TiO2. Impedance analysis illustrates the role of carbonate treatment in increasing the recombination resistance at the photoanode/electrolyte interfaces and in suppressing back-electron transfer to the electrolyte, thus validating the superior PCE achieved for the cell with carbonate-treated TiO2. QDSCs with the configuration TiO2-CBN/CdS/Au@PAA-polysulfide/SiO2 gel-carbon-fabric/WO3-x and active areas of 0.2-0.3 cm2 yield efficiencies in the range of 5.16 to 6.3%, and the average efficiency of the cells is 5.9%. The champion cell is characterized by the following photovoltaic parameters: JSC (short circuit current density), 11.04 mA cm-2; VOC (open circuit voltage), 0.9 V; FF, 0.63; and PCE, 6.3%. Stability tests performed on this cell show that dark storage has a less deleterious effect on cell performance compared to extended illumination. In dark, the PCE of the cell dropped from 5.69 to 5.52%, and under prolonged continuous irradiance of 5 h, it decreased from 5.91 to 4.83%. A scaled-up QDSC with the same architecture of 4 cm2 size showed a PCE of 1.06%, and the demonstration of the lighting of a LED accomplished using this cell exemplifies that this cell can be used for powering electronic devices that require low power.

Electrochemical Impedance Analysis of Biofunctionalized Conducting Polymer-Modified Graphene-CNTs Nanocomposite for Protein Detection.

We report an electrodeposited poly(pyrrole-co-pyrrolepropylic acid) copolymer modified electroactive graphene-carbon nanotubes composite deposited on a glassy carbon electrode to detect the protein antigen (cTnI). The copolymer provides pendant carboxyl groups for the site-specific covalent immobilization of protein antibody, anti-troponin I. The hybrid nanocomposite was used as a transducer for biointerfacial impedance sensing for cTnI detection. The results show that the hybrid exhibits a pseudo capacitive behaviour with a maximum phase angle of 49° near 1 Hz, which is due to the inhomogeneous and porous structure of the hybrid composition. The constant phase element of copolymer is 0.61 (n = 0.61), whereas, it is 0.88 (n = 0.88) for the hybrid composites, indicating a comparatively homogeneous microstructure after biomolecular functionalization. The transducer shows a linear change in charge transfer characteristic (R et) on cTnI immunoreaction for spiked human serum in the concentration range of 1.0 pg mL-1-10.0 ng mL-1. The sensitivity of the transducer is 167.8 ± 14.2 Ω cm2 per decade, and it also exhibits high specificity and good reproducibility.

Large Area Fabrication of Semiconducting Phosphorene by Langmuir-Blodgett Assembly.

Phosphorene is a recently new member of the family of two dimensional (2D) inorganic materials. Besides its synthesis it is of utmost importance to deposit this material as thin film in a way that represents a general applicability for 2D materials. Although a considerable number of solvent based methodologies have been developed for exfoliating black phosphorus, so far there are no reports on controlled organization of these exfoliated nanosheets on substrates. Here, for the first time to the best of our knowledge, a mixture of N-methyl-2-pyrrolidone and deoxygenated water is employed as a subphase in Langmuir-Blodgett trough for assembling the nanosheets followed by their deposition on substrates and studied its field-effect transistor characteristics. Electron microscopy reveals the presence of densely aligned, crystalline, ultra-thin sheets of pristine phosphorene having lateral dimensions larger than hundred of microns. Furthermore, these assembled nanosheets retain their electronic properties and show a high current modulation of 104 at room temperature in field-effect transistor devices. The proposed technique provides semiconducting phosphorene thin films that are amenable for large area applications.

Interactions of titania based nanoparticles with silica and green-tea: Photo-degradation and -luminescence.

An effective way to modify the photocatalytic activity of both anatase and rutile TiO2 nanoparticles by coating the surface with either an inorganic (SiO2/silica) or organic (green-tea) layer using a chemical approach is demonstrated. Tetraethyl orthosilicate (TEOS) was used to cover the surface of TiO2 with silica which facilitates the inhibition of photocatalytic activity, ensuring its application in sunscreens by blocking the reactive oxygen species (ROS). Green-tea extract, rich in epigallocatechin gallate (EGCG), was used to coat/stabilize nano-sized TiO2. The morphology of these coatings was revealed by transmission electron microscopy (TEM) and by energy dispersive spectroscopy (EDS) mapping. These studies showed good coverage for both types of coating, but with somewhat better uniformity of the coating layer on rutile TiO2 compared to anatase due to its more uniform particle geometry. The effectiveness of each coating was evaluated by photodegradation of an organic dye (methyl orange). These studies showed rutile_polyphenol exhibits the highest photocatalytic activity among rutile forms which validates its feasibility to be used in photodegradation.

Synthesis and characterization of reduced graphene oxide supported gold nanoparticles-poly(pyrrole-co-pyrrolepropylic acid) nanocomposite-based electrochemical biosensor.

A conducting poly(pyrrole-co-pyrrolepropylic acid) copolymer nanocomposite film (AuNP-PPy-PPa) incorporating gold nanoparticles (AuNP) was electrochemically grown using a single step procedure over electrochemically reduced graphene oxide (RGO) flakes deposited on a silane-modified indium-tin-oxide (ITO) glass plate. The RGO support base provided excellent mechanical and chemical stability to the polymer nanocomposite matrix. The porous nanostructure of AuNP-PPy-PPa/RGO provided a huge accessible area to disperse AuNP, and it avoided metallic agglomeration within the polymer matrix. The AuNP-PPy-PPa/RGO was characterized by high-resolution transmission electron microscopy (HRTEM), contact angle measurements, Fourier transform infrared spectroscopy (FTIR), and electrochemical techniques. The pendant carboxyl group of AuNP-PPy-PPa/RGO was covalently bonded with myoglobin protein antibody, Ab-Mb, for the construction of a bioelectrode. Electrochemical impedance spectroscopy technique was used for the characterization of the bioelectrode and as an impedimetric biosensor for the detection of human cardiac biomarker, Ag-cMb. The bioelectrode exhibited a linear impedimetric response to Ag-cMb in the range of 10 ng mL(-1) to 1 µg mL(-1), in phosphate-buffered solution (PBS) (pH 7.4, 0.1 M KCl) with a sensitivity of 92.13 Ω cm(2) per decade.

Microstructural and potential dependence studies of urease-immobilized gold nanoparticles-polypyrrole composite film for urea detection.

Gold nanoparticle-polypyrrole nanocomposite film was electrochemically deposited in a single-step polymerization of pyrrole in the presence of 3-mercaptopropionic acid (MPA)-capped gold nanoparticles (GNPs) and p-toluenesulfonic acid (pTSA) on the surface of an indium tin oxide (ITO)-coated glass plate. The carboxyl functional groups surrounding the GNPs within the polymer matrix were utilized for the immobilization of urease enzyme through carbodiimide coupling reaction for the construction of a Urs/GNP(MPA)-PPy/ITO-glass bioelectrode for urea detection in Tris-HCl buffer. The resulting bioelectrode film was characterized by atomic force microscopy (AFM), high-resolution transmission electron microscopy (HRTEM), contact angle measurement, Fourier transform infrared spectroscopy (FTIR), and electrochemical techniques. The potentiometric response of the bioelectrode made of polymer nanocomposite films of two different thicknesses prepared at 100 and 250 mC cm(-2) charge densities, respectively, was studied towards the urea concentration in Tris-HCl buffer (pH 7.4). The thin polymer nanocomposite film-based bioelectrode prepared at 100 mC cm(-2) charge density exhibited a comparatively good potentiometric response than a thick 250 mC cm(-2) charge density film with a linear range of urea detection from 0.01 to 10 mM with a sensitivity of 29.7 mV per decade.

Microstructural and electrochemical impedance characterization of bio-functionalized ultrafine ZnS nanocrystals-reduced graphene oxide hybrid for immunosensor applications.

We report a mercaptopropionic acid capped ZnS nanocrystals decorated reduced graphene oxide (RGO) hybrid film on a silane modified indium-tin-oxide glass plate, as a bioelectrode for the quantitative detection of human cardiac myoglobin (Ag-cMb). The ZnS nanocrystals were anchored over electrochemically reduced GO sheets through a cross linker, 1-pyrenemethylamine hydrochloride, by carbodiimide reaction and have been characterized by scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. The transmission electron microscopic characterization of the ZnS-RGO hybrid shows the uniform distribution of ultra-fine nanoparticles of ZnS in nano-sheets of GO throughout the material. The protein antibody, Ab-cMb, was covalently linked to ZnS-RGO nanocomposite hybrid for the fabrication of the bioelectrode. A detailed electrochemical immunosensing study has been carried out on the bioelectrode towards the detection of target Ag-cMb. The optimal fitted equivalent circuit model that matches the impedance response has been studied to delineate the biocompatibility, sensitivity and selectivity of the bioelectrode. The bioelectrode exhibited a linear electrochemical impedance response to Ag-cMb in a range of 10 ng to 1 µg mL(-1) in PBS (pH 7.4) with a sensitivity of 177.56 Ω cm(2) per decade. The combined synergistic effects of the high surface-to-volume ratio of ZnS(MPA) nanocrystals and conducting RGO has provided a dominant charge transfer characteristic (R(et)) at the lower frequency region of <10 Hz showing a good biocompatibility and enhanced impedance sensitivity towards target Ag-cMb. The impedance response sensitivity of the ZnS-RGO hybrid bioelectrode towards Ag-cMb has been found to be about 2.5 fold higher than that of a bare RGO modified bioelectrode.

Alumina-supported oxime for the degradation of sarin and diethylchlorophosphate.

1-(4-Chlorophenyl))-N-hydroxymethanimine and cyclohexyl-N-hydroxymethanimine were synthesized and a well-established oxime, i.e., 2-[(hydroxyimino)methyl]-1-methylpyridinium chloride was purchased. Thereafter; all were loaded over Al(2)O(3) using incipient wetness technique. The prepared systems were characterized using surface area analyzer, scanning electron microscope, energy dispersive X-ray spectrophotometer, Fourier transform infrared spectrophotometer and thermogravimetric analyzer. Kinetics of the degradation of sarin (GB) and simulant, i.e. diethylchlorophosphate (DEClP) was studied over synthesized oxime impregnated Al(2)O(3) and results were compared with well reported oxime impregnated Al(2)O(3). Kinetics of reaction was found to be following the pseudo first order reaction kinetics. The order of reactivity of the prepared systems was found to be cyclohexyl-N-hydroxymethanimine/Al(2)O(3)>1-(4-chlorophenyl)-N-hydroxymethanimine/Al(2)O(3)>2-[(hydroxyimino)methyl]-1-methylpyridinium chloride/Al(2)O(3)>Al(2)O(3). From the reaction kinetics it was observed that the reaction with DEClP was faster than with GB. Cyclohexyl-N-hydroxymethanimine/Al(2)O(3) was found to be the most reactive system with half-life of 0.94 and 15 h for DEClP and GB respectively.

Kinetics of degradation of sulfur mustard and sarin simulants on HKUST-1 metal organic framework.

The applicability of HKUST-1 for the degradation of sulfur mustard and sarin simulants was studied with and without coadsorbed water. Degradation was found to be via hydrolysis and dependent on the nucleophilic substitution reaction, vapour pressure and molecular diameter of the toxicants.

Removal of sulphur mustard, sarin and simulants on impregnated silica nanoparticles.

Silica nanoparticles of diameter, 24-75 nm and surface area, 875 m(2)/g were synthesized using aero-gel route. Thereafter, nanoparticles were impregnated with reactive chemicals, and used as reactive adsorbent to study the removal of toxic nerve and blister chemical warfare agents and their simulants from solutions. Trichloroisocyanuric acid impregnated silica nanoparticles showed the best performance and indicated physisorption followed by chemisorption/degradation of toxicants. This indicated their suitability as universal decontaminant for nerve and blister agents. This system showed a decrease in t(1/2) from 1210 to 2.8 min for the removal of king of chemical warfare agents, i.e., sulphur mustard. Hydrolysis, dehydrohalogenation and oxidation reactions were found to be the route of degradation of toxicants over impregnated silica nanoparticles.