Nanodiamonds: A Cutting-Edge Approach to Enhancing Biomedical Therapies and Diagnostics in Biosensing.

Nanodiamonds (NDs) have garnered attention in the field of nanomedicine due to their unique properties. This review offers a comprehensive overview of NDs synthesis methods, properties, and their uses in biomedical applications. Various synthesis techniques, such as detonation, high-pressure, high-temperature, and chemical vapor deposition, offer distinct advantages in tailoring NDs' size, shape, and surface properties. Surface modification methods further enhance NDs' biocompatibility and enable the attachment of bioactive molecules, expanding their applicability in biological systems. NDs serve as promising nanocarriers for drug delivery, showcasing biocompatibility and the ability to encapsulate therapeutic agents for targeted delivery. Additionally, NDs demonstrate potential in cancer treatment through hyperthermic therapy and vaccine enhancement for improved immune responses. Functionalization of NDs facilitates their utilization in biosensors for sensitive biomolecule detection, aiding in precise diagnostics and rapid detection of infectious diseases. This review underscores the multifaceted role of NDs in advancing biomedical applications. By synthesizing NDs through various methods and modifying their surfaces, researchers can tailor their properties for specific biomedical needs. The ability of NDs to serve as efficient drug delivery vehicles holds promise for targeted therapy, while their applications in hyperthermic therapy and vaccine enhancement offer innovative approaches to cancer treatment and immunization. Furthermore, the integration of NDs into biosensors enhances diagnostic capabilities, enabling rapid and sensitive detection of biomolecules and infectious diseases. Overall, the diverse functionalities of NDs underscore their potential as valuable tools in nanomedicine, paving the way for advancements in healthcare and biotechnology.

A NiO-nanostructure-based electrochemical sensor functionalized with supramolecular structures for the ultra-sensitive detection of the endocrine disruptor bisphenol S in an aquatic environment.

Herein, NiO nanoparticles (NPs) functionalized with a para-hexanitrocalix[6]arene derivative (p-HNC6/NiO) were synthesized by using a facile method and applied as a selective electrochemical sensor for the determination of bisphenol S (BPS) in real samples. Moreover, the functional interactions, phase purities, surface morphologies and elemental compositions of the synthesized p-HNC6/NiO NPs were investigated via advanced analytical tools, such as Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). Additionally, the synthesized p-HNC6/NiO NPs were cast on the surface of a bare glassy carbon electrode (GCE) via a drop casting method, which resulted in uniform deposition of p-HNC6/NiO/GCE over the surface of the GCE. Additionally, the developed p-HNC6/NiO/GCE sensor demonstrated an outstanding electrochemical response to BPS under optimized conditions, including a supporting electrolyte, a Briton-Robinson buffer electrolyte at pH 4, a scan rate of 110 mV s-1 and a potential window of between -0.2 and 1.0 V. The wide linear dynamic range was optimized to 0.8-70 µM to obtain a brilliant linear calibration curve for BPS. The limit of detection (LOD) and limit of quantification (LOQ) of the developed sensor were estimated to be 0.0059 and 0.019 µM, respectively, which are lower than those of reported sensors for BPS. The feasibility of the developed method was successfully assessed by analyzing the content of BPS in waste water samples, and good recoveries were achieved.

Fabrication of para-dimethylamine calix[4]arene functionalized self-assembled graphene oxide composite material for effective removal of 2, 4, 6-tri-Cholorphenol from aqueous environment.

Water pollution caused by the release of organic pollutants is a major environmental concern worldwide. These pollutants can have harmful effects on aquatic ecosystems and the organisms living within them, as well as on human health when contaminated water is consumed. It is essential to implement proper treatment and management strategies to prevent and mitigate water pollution. Moreover, the major untreated industrial effluents are synthetic organic compounds especially 2,4,6-trichlorophenol (TCP) which cause several environmental issues and heath related problems in humans. To cope with this problem, an excellent 2D porous material based on p-DMAC4/GO composite has been synthesized as adsorbent material for the effective removal of 2,4,6-trichlorophenol pollutant from wastewater. In this regard, the advanced analytical tools such as Fourier-Transform infrared (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray spectroscopy (EDS) were used for its characterization. The results justified the chemical composition, excellent crystalline nature, surface morphology and elemental composition of the synthesized composite material. The synthesized adsorbent material showed 95% adsorption of TCP from wastewater system at optimal conditions i.e., pH (6), adsorbent dosage (30 mg) and shaking time (60 min). The mathematical models such as isotherms, thermodynamics and kinetics studies validate the nature of adsorption process of TCP pollutant. The adsorption data found to be best fitted with Langmuir isotherms (R2 = 0.99); whereas kinetic study suggested the pseudo-second-order nature of reaction with R2 = 0.99. The thermodynamics study confirmed the spontaneous and endothermic nature of the TCP pollutant onto the surface of p-DMAC4/GO material. Moreover, the results of current work were also compared with existing reported adsorbents and data suggested the higher efficiency, feasibility, and reusability of p-DMAC4/GO material to remove the TCP pollutant from the wastewater system.

Physical properties and pharmacological applications of Co3O4, CuO, NiO and ZnO nanoparticles.

Nano materials have found developing interest in biogenic approaches in the present times. In this study, metal oxide nanoparticles (NPs) such as cobalt oxide (Co3O4), copper oxide (CuO), nickel oxide (NiO) and zinc oxide (ZnO), were synthesized using a convenient and rapid method. The structural features of synthesized metal oxide NPs were studied using various microscopic and spectroscopic techniques like SEM, TEM, XRD, FTIR and EDX. The characterization results confirmed that the prepared NPs possess highly pure, unique and crystalline geometry with size ranging between 10 and 20 nm. The synthesized nanoparticles were successfully employed for pharmacological applications. Enzyme inhibition potential of NPs was evaluated against the urease and tyrosinase enzymes. The percent inhibition for the urease enzyme was observed as 80 to 90% by using Co3O4, CuO, NiO and ZnO NPs while ZnO NPs were found to have best anti-urease and anti-tyrosinase activities. Moreover, effective inhibition was observed in the case of ZnO NPs at IC50 values of 0.0833 and 0.1732 for urease and tyrosinase enzymes which were comparable to reference drugs thiourea and kojic acid. The lower the IC50 value, higher the free radical scavenging power. Antioxidant activity by DPPH free radical scavenging method was found moderately high for the synthesized metal oxide NPs while best results were obtained for Co3O4 and ZnO NPs as compared to the standard ascorbic acid. Antimicrobial potential was also evaluated via the disc diffusion and well diffusion methods. CuO NPs show a better zone of inhibition at 20 and 27 mm by using both methods. This study proves that the novel metal oxide NPs can compete with the standard materials used in the pharmacological studies nowadays.

Pharmacological assessment of Co3O4, CuO, NiO and ZnO nanoparticles via antibacterial, anti-biofilm and anti-quorum sensing activities.

Infectious diseases have risen dramatically as a result of the resistance of many common antibiotics. Nanotechnology provides a new avenue of investigation for the development of antimicrobial agents that effectively combat infection. The combined effects of metal-based nanoparticles (NPs) are known to have intense antibacterial activities. However, a comprehensive analysis of some NPs regarding these activities is still unavailable. This study uses the aqueous chemical growth method to synthesize Co3O4, CuO, NiO and ZnO NPs. The prepared materials were characterized by scanning electron microscopy, transmission electron microscopy and X-ray diffraction techniques. The antibacterial activities of NPs were tested against Gram-positive and Gram-negative bacteria using the microdilution method, such as the minimum inhibitory concentration (MIC) method. The best MIC value among all the metal oxide NPs was 0.63 against Staphylococcus epidermidis ATCC12228 through ZnO NPs. The other metal oxide NPs also showed satisfactory MIC values against different test bacteria. In addition, the biofilm inhibition and antiquorum sensing activities of NPs were also examined. The present study presents a novel approach for the relative analysis of metal-based NPs in antimicrobial studies, demonstrating their potential for bacteria removal from water and wastewater.

Exploring the Mechanism of Anionic Chemosensing by Imidazoles: A Review.

Chemosensing of ions has gained considerable attention by chemists. Insight into the mechanism involved between sensors and ions always fascinates researchers to develop economical, sensitive, selective, and robust sensors. This review comprehensively explores the mechanism of interaction between Imidazole sensors and anions. With most of the research concentrating only on fluoride and cyanide, this review has highlighted a large gap in various anions detection including SCN-, Cr2O72-, CrO42-, H2PO4-, NO2-, and HSO4-.This study also includes a critical analysis of different mechanisms and their respective limits of detection, with a discussion of the reported results.

Fluorene intercalated graphene oxide based CoQ10 imprinted polymer composite as a selective platform for electrochemical sensing of CoQ10.

The new objective of sustainable analytical chemistry is to develop validated robust, swift, simple and highly sensitive analytical methods that are based on cost effective sensing technology. Therefore, in this study the electro-chemical detection of coenzyme Q10 (CoQ10) was achieved using a fluorene intercalated graphene oxide based CoQ10 imprinted polymer composite modified glassy carbon electrode (CoQ10-IGOPC/GCE). The synthesized sensing material was characterized using SEM, XRD and FT-IR to determine the morphology and functional properties. The CoQ10-IGOPC/GCE was characterized by EIS for its electrochemical properties. CoQ10 was detected selectively using Differential Pulse Voltammetry (DPV). Under ideal circumstances, a linear calibration curve with a correlation coefficient (R 2) of 0.991 was produced in the concentration range of 0.0967 to 28.7 µM. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.029 and 0.0967 µM, respectively. Furthermore, the proposed electrochemical sensor was extremely selective, accurate and thoroughly validated with RSD values less than 5%. The developed CoQ10-IGOPC/GCE based electrochemical sensor was successfully used for the detection of CoQ10 in samples of fruits, vegetables, nuts, human blood serum and pharmaceuticals. The CoQ10-IGOPC/GCE based electrochemical method showed good percent recoveries ranging from 94 to 103 percent.

Sulfonamides as Optical Chemosensors.

Sulfonamides are auspicious chemosensors which are capable to bind with ionic species through various ways like complexation, charge transfer, proton transfer etc. and produce a detection signal in the form of an optical change either in visible or UV-light and for electronic as well as fluorimetric spectra. Sulfonamides have gained much attention of analytical chemists these days as these are inexpensive, robust, green in nature and some what sensitive and selective to many anionic and cationic species. Due to their promising versatility in sensing properties, these are under great consideration in forensic, environmental, analytical and biochemistry laboratories. This review narrates how sulfonamides are being used to optically sense ionic species.

HIGHLIGHTSOptical sensors are of great importance these days because of their optical detection properties rather using Hi-tech techniques.Optical sensors are economical, robust, selective, sensitive and green in nature.The color change, shifts in electronic spectra or alterations in fluorescence pattern may be attributed by interaction between species to be sensed and Sulfonamides by different mechanism i.e. electron transfer, fluorescence energy transfer, charge transfer, hydrogen bonding, etc.LOD data is a proof of their prodigious efficiency of Sulfonamides as optical sensors.

Facile Synthesis of NiO/ZnO nanocomposite as an effective platform for electrochemical determination of carbamazepine.

The pharmaceutical science demand for sustainable and selective electrochemical sensors which exhibit ultrasensitive capabilities for the monitoring of different drugs. In an attempt to build a useful electrochemical sensor, we describe a most efficient method for the fabrication of NiO/ZnO nanocomposite through aqueous chemical growth method. The successfully synthesized NiO/ZnO nanocomposite is successfully employed to modify a glassy carbon electrode in order to build a sensitive and reliable electrochemical sensor for the detection of carbamazepine (CBZ), an anticonvulsant drug. The morphological texture, functionalities and crystalline structure of prepared nanocomposite were determined via FTIR, XRD, EDX, TEM, and SEM analysis. In order to examine the charge transfer kinetics, the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to exploit the electrochemical properties of the synthesized nanocomposite. The NiO/ZnO nanocomposite exhibited excellent electron transfer kinetics and less resistive behavior than the individual NiO and ZnO nanoparticles. The differential pulse voltammetry and cyclic voltammetry tools were used for the fluent determination of CBZ. Certain parameters were optimized to develop an effective method including optimum scan rate 60 mV/s, potential range from 0.4 to 1.4 V and BRB as supporting electrolyte with pH 3. The developed sensor showed exceptional response for CBZ under the linear dynamic range from 5 to 100 µM. The limit of detection of proposed NiO/ZnO sensor for the CBZ was calculated to be 0.08 µM. The analytical approach of prepared electrochemical sensor was investigated in different pharmaceutical formulation with acceptable percent recoveries ranging from 96.7 to 98.6%.

Selective oxidation of amaranth dye in soft drinks through tin oxide decorated reduced graphene oxide nanocomposite based electrochemical sensor.

The recent studies evaluated the extensive exploitation of azo dyes as food colorant to improve the texture of food to turn the food to be very attractive. The heavy consumption of the food colorants by the food industries in commonly consumed beverages especially in the soft drinks may become the cause of certain suspected diseases. Amaranth is an azo dye which easily cleaved into amines and is suspected to be mutagen and carcinogen. Thus, the quantification of amaranth through reliable and sensitive sensor is of great importance. The SnO2/rGO nanocomposite has been engineered to be utilized as chemically modified sensor for the low-level quantification of amaranth in soft drinks and water sample. The fabricated nanocomposite materials was characterized through XRD, FTIR, raman and TEM tools which revealed average crystalline size of 23.7 nm, different surface functionalities and internal rectangle shaped morphology. The engineered nanocomposite was electrochemically characterized through electrochemical impedance spectroscopy (EIS) and Tafel plot to evaluate the electrocatalytic properties and charger transfer kinetics of SnO2/rGO/Nafion/GCE. The resistance of bare, GO/GCE and SnO2/rGO/Nafion/GCE was calculated as 812.5 Ω, 1343 Ω and 338 Ω. Certain parameters were optimized such as PBS electrolyte pH 6, scan rate 130 mV/s and potential window (0.4-1.2 V) to carry out sensitive and fluent determination process of amaranth azo dye. For the effectiveness of proposed sensor two calibration ranges were optimized from 1 to 800 nM and 1-60 µM. The LOD for both ranges were calculated as 0.68 nM and 0.0027 µM. Moreover, the anti-interference and stability profile of developed sensor were found phenomenal that suggest the exceptional electrocatalytic performance of SnO2/rGO/Nafion/GCE for amaranth.

Fabrication of sensor based on polyvinyl alcohol functionalized tungsten oxide/reduced graphene oxide nanocomposite for electrochemical monitoring of 4-aminophenol.

4-aminophenol (4-AP) is one of the major environmental pollutants which is broadly exploited as drug intermediate in the pharmaceutical formulations. The extensive release of 4-AP in the environment without treatment has become a serious issue that has led several health effects on humans. This work describe the determination of 4-AP through a new chemically modified sensor based on polyvinyl alcohol functionalized tungsten oxide/reduced graphene oxide (PVA/WO3/rGO) nanocomposite. The fabricated nanocomposite was characterized through XRD and HR-TEM to confirm the crystalline structure with average size of 35.9 nm and 2D texture with ultra-fine sheets. The electrochemical characterization of fabricated sensor was carried out by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) to ensure the charge transfer kinetics of modified sensor that revealed high conductivity of PVA/WO3/rGO/GCE. Under optimized conditions e.g. scan rate 80 mV/s, phosphate buffer (pH 6) as supporting electrolyte and potential window from -0.2 to 0.8 V, the prepared sensor showed excellent response for 4-AP. The linear dynamic range of developed method was optimized as 0.003-70 µM. The LOD of fabricated sensor based on PVA/WO3/rGO/GCE for 4-AP was calculated as 0.51 nM. The practical application of PVA/WO3/rGO/GCE was tested in real water and pharmaceutical samples. The fabricated sensor presented here, exhibited exceptional stability and sensitivity than the reported sensors and could be effectively used for the monitoring 4-AP without interferences.

Electrochemical monitoring of bisphenol-s through nanostructured tin oxide/Nafion/GCE: A solution to environmental pollution.

Over the past few decades, phenolic compounds have been broadly exploited in the industries to be utilized in several applications including polycarbonate plastic, food containers, epoxy resins, etc. One of the major compounds in phenolics is Bisphenol-S (BPS) which has dominantly replaced Bisphenol-A in several applications. Phenolic compounds are extensively drained into the environment without proper treatment and cause several health hazards. Thus, to tackle this serious problem an electrochemical sensor based on SnO2/GCE has been successfully engineered to monitor the low-level concentration of BPS in water samples. The fabrication of SnO2 nanoparticles (SnO2 NPs) was confirmed through FTIR, XRD, and TEM to examine the size, crystallinity, internal texture, and functionalities of the prepared material. The fabricated material was exploited as a chemically modified sensor for the determination of BPS in water samples collected from different sources. Under optimal conditions such as scan sweep 100 mV/s, PBS electrolyte pH of 6, potential window (0.3-1.3 V), the proposed sensor manifested an excellent response for BPS. The LOD of the present method for BPS was calculated as 0.007 µM, respectively. Moreover, the stability and selectivity profile of SnO2/GCE for BPS in the real matrix was examined to be outstanding.

Natural and anthropogenic origin of metallic contamination and health risk assessment: A hydro-geochemical study of Sehwan Sharif, Pakistan.

Heavy metal contamination in groundwater is a serious threat to the environment and therefore its proper monitoring is a matter of great concern these days. In the present research, groundwater samples from Sehwan Sharif district Jamshoro, Pakistan were collected to estimate the concentration of various elements including potentially hazardous metals. Statistical analysis of the collected data based on Pearson co-relation metal clustering and Principal Component Analysis (PCA) divides the elements into three groups; Group I contains As, Cu, Ni, and Cd, Group II contains Mn, Fe, B, and Cr and Group III contains Pb and Zn. The elements Cu, Ni, As, Pb, Cd, and Zn found with higher RSD values demonstrate their anthropogenic origin whereas the lower concentration of Mn, Fe, B, and Cr indicate their natural origin (Tepanosyan et al., 2016). The histograms and box-plots of Mn, Fe, B and Cr were found normally distributed while abnormal for Cu, Ni, Pb, As, Cd and Zn. The HQs of these elements indicate their non-carcinogenic risks. However, results of individual metallic behavior indicate the highest HQ measured for B followed by HQs for Cu, and As. The toxic effects of investigated metal (loid)s calculated using HI were found to be 1.58 for adults and 1.35 for the child which is considered the medium chromic risk and cancer risk. About the toxicity of these heavy metals, their cancer risk was assessed on the levels of Cd, As, and Cr in groundwater. The carcinogenic risk of As was found to be 2.78 × 10-4 and 1.62 × 10-3 for child and adult, respectively. Furthermore, the values of this carcinogenic risk are 2.64 × 10-6 and 1.54 × 10-5 for Cd while 4.24 × 10-3 and 2.48 × 10-2 for Cr in child and adult, respectively. Since cancer risk exceeded the target risk of 1 × 10-4 for As and Cr in adults and children, it can thus be considered 'non-acceptable'. The Geographic Information System (GIS) based maps were prepared using Inverse Distance Weighted (IDW) interpolation which showed the Spatial distribution of all elements throughout Sehwan Sharif from different sources of environment. Spatial maps of elements produced by ArcGIS show the hotspots of potentially hazardous elements such as the highest concentration of Pb, As, Zn, Cu, Ni, and Cd were found in urban areas of Sehwan Sharif district Jamshoro, Pakistan.

An improved electrochemical sensor based on triton X-100 functionalized SnO2 nanoparticles for ultrasensitive determination of cadmium.

The drastic increases in the concentration of heavy metals ions in the environment have become a serious concern for a number of years. Heavy metals pose serious impacts on human and aquatic life and cause severe health hazards. Amongst heavy metals, cadmium is known for its lethal effects on human health as it easily reacts with enzymes and creates free radicals in the biological system that causes carcinogenicity and other serious diseases. Thus, to tackle this challenge, TX-100 SnO2 nanoparticles based chemically modified sensor is introduced to assess the quantity of Cd+2 in the water system. The engineered SnO2 nanoparticles were electrochemically characterized through cyclic voltammetry and electrochemical impedance spectroscopy to ensure the better charge transfer kinetics and electrocatalytic properties of fabricated sensors. Under the optimized conditions e.g., scan rate 80 mV/s, PBS electrolyte pH 7, and potential window (-0.2 to -1.4 V), the engineered TX-100/SnO2/GCE-based sensor manifested a phenomenal response for cadmium ions in water media. The LOD and LOQ of developed TX-100/SnO2/GCE were calculated in the nanomolar range as 0.0084 nM and 0.27 nM. The recovery values of the proposed method for Cd+2 were found in an acceptable limit that witnesses the effectiveness of the fabricated sensor. Moreover, the excellent stability and anti-interference behavior of the sensor highlights its dynamic profile to be commercially utilized for the determination of Cd+2 ions in water bodies.

Electrochemical quantification of mancozeb through tungsten oxide/reduced graphene oxide nanocomposite: A potential method for environmental remediation.

The extensive use of pesticides for better yield of crops have become major human concern over the decades. Pesticides are widely used in the fields to kill weeds and pests on the vegetable and crops to improve the quality and yield of the food knowing the fact that pesticides residue in food are very lethal for human being. Amongst, the hazardous pesticides, mancozeb is widely applied in the protection of crops. Thus the quantification of mancozeb residue is of great importance. This study reports the electrochemical monitoring of mancozeb through tungsten oxide reduced graphene oxide (WO3/rGO) nanocomposite. The engineered nanocomposite was characterized though different analytical tools such as FTIR, XRD and TEM to examine crystallinity, internal texture and the size. The FTIR result confirm the functionalities of GO and WO3/rGO nanocomposite in finger print and functional group region. Through XRD analysis, the size of the WO3/rGO nanocomposite was calculated as 31.6 nm. While the TEM analysis was also exploited to examine the 2D texture of GO and nanometric size of the WO3/rGO. To ensure the conductive nature of the WO3/rGO nanocomposite, the glassy carbon electrode was modified and exploited for cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimal conditions, the modified sensor showed exceptional response for mancozeb. The linear dynamic range was set from 0.05 to 70 µM in BRB buffer of pH 4. The LOD and LOQ for proposed method was calculated as 0.0038 and 0.0115 µM. The analytical applicability of chemically modified sensor was investigated in real matrix of different vegetable samples and the recovery values were observed in acceptable range. The electrochemical examination of present work reveals that WO3/rGO nanocomposite can be an exceptional aspirant for the determination of mancozeb at commercial level.

Spatial analysis and human health risk assessment of elements in ground water of District Hyderabad, Pakistan using ArcGIS and multivariate statistical analysis.

Availability of clean drinking water is a basic necessity of human population. Therefore, the current study was taken up for spatial analysis and human health risk assessment of elements in Ground water of District Hyderabad, Pakistan. Evaluation of 10 potential hazardous elements in one hundred eighteen samples of ground water from district Hyderabad, Pakistan was done to assess their natural and anthropogenic origin and possible effects on living organisms and human health. Based on statistical tools of Pearson Co-relation, Metal Clustering and Principal Component Analysis (PCA), three groups of elements were produced; First group included Mn, Fe, B and Cr, the second group contained Cu, Ni and As while third group included Pb, Cd and Zn. Higher Relative Standard Deviation (RSD) values of Cu, Ni, As, Pb, Cd and Zn showed their anthropogenic origin while Mn, Fe, B and Cr were found with lower concentration that indicated their natural origin. Histograms and box-plots of Mn, Fe, B and Cr were found to be normally distributed while these parameters were appeared abnormal for Cu, Ni, As, Pb, Cd and Zn. Risk assessment was quantified by hazard quotient (HQ) and cancer risk for both adult and child. Non-carcinogenic risks as depicted by HQs of all the 10 metal(loid)s were below the recommended HQ threshold of 1 for both child and adult. However, highest HQ was calculated for B (child 0.300 and adult 0.338) followed by the values for Mn and Ni. The potential risks of combined effect of all the 10 metal(loid)s through ingestion of groundwater was assessed using HI and calculated to be 0.694 for adult and 0.566 for child. This indicates the potential health risk of these metal(loid)s to human due to the consumption of the groundwater of district Hyderabad for drinking purpose. Considering the geometric mean for the studied area, carcinogenic risk of As through oral intake was calculated i.e. 1.50 × 10-4 and 2.62 × 10-5 for the adult and child However, this carcinogenic risk is 1.91 × 10-5 and 3.28 × 10-6 for Cd in adult and child and 1.94 × 10-3 and 3.32 × 10-4 for Cr in adult and child, respectively. Since the cancer risk 6exceeded the target risk of 1 × 10-4 for Cr i.e. 1.94 × 10-3 in adult, it can thus be considered as 'non-acceptable'. Spatial maps of elements produced by ArcGIS showed the hotspots of potential hazardous elements such as highest concentration of elements like Zn, Pb and Cd was found in urban areas while highest concentration of Cu, Ni and As was observed near Phulleli canal which passes from Hyderabad City and may contain contamination from waste material of residential area due to their anthropogenic activities.

Plant extract-based green fabrication of nickel ferrite (NiFe2O4) nanoparticles: An operative platform for non-enzymatic determination of pentachlorophenol.

Environmental pollution has become a major human concern with the extensive exploitation of pesticides. Pentachlorophenol (PCP) is the most hazardous of all chlorophenols which are being used as pesticide, fungicide, and wood preservative. Thus, the fabrication of ultrasensitive electrochemical methods for the determination of pesticides is of great significance. In the present experiment, a simple, green, and sensitive electrochemical sensor was constructed for the determination of PCP by using a chemically modified nickel ferrite glassy carbon electrode (NiFe2O4/GCE). The fabricated nanoparticles were primarily characterized by several analytical tools to confirm the functionalities, surface texture, crystallinity, and elemental composition. For the investigation of conductive nature, the proposed NiFe2O4/GCE was exploited to the primary electrochemical characterization tools e.g. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The ultra-sensitive determination of PCP was carried out under the linear dynamic range from 0.01 to 90 µM at the pulse amplitude of 80 mV/s in BRB buffer pH of 4. The limit of detection of the developed methods for PCP was calculated to be 0.0016 µM. The analytical applicability of the fabricated sensor was tested in different water samples depicting the acceptable recovery values.

Identification of heavy metal ions from aqueous environment through gold, Silver and Copper Nanoparticles: An excellent colorimetric approach.

Heavy metal pollution has become a severe threat to human health and the environment for many years. Their extensive release can severely damage the environment and promote the generation of many harmful diseases of public health concerns. These toxic heavy metals can cause many health problems such as brain damage, kidney failure, immune system disorder, muscle weakness, paralysis of the limbs, cardio complaint, nervous system. For many years, researchers focus on developing specific reliable analytical methods for the determination of heavy metal ions and preventing their acute toxicity to a significant extent. The modern researchers intended to utilize efficient and discerning materials, e.g. nanomaterials, especially the metal nanoparticles to detect heavy metal ions from different real sources rapidly. The metal nanoparticles have been broadly utilized as a sensing material for the colorimetric detection of toxic metal ions. The metal nanoparticles such as Gold (Au), Silver (Ag), and Copper (Cu) exhibited localized plasmon surface resonance (LPSR) properties which adds an outstanding contribution to the colorimetric sensing field. Though, the stability of metal nanoparticles was major issue to be exploited colorimetric sensing of heavy emtal ions, but from last decade different capping and stabilizing agents such as amino acids, vitmains, acids and ploymers were used to functionalize the metal surface of metal nanoparticles. These capping agents prevent the agglomeration of nanoparticles and make them more active for prolong period of time. This review covers a comprehensive work carried out for colorimetric detection of heavy metals based on metal nanoparticles from the year 2014 to onwards.

Carbon dots as naked eye sensors.

Optical sensors are always fascinating for chemists due to their selectivity, sensitivity, robustness and cost-effective nature. Moreover, these sensors provide the facility of onsite detection without employing any instrumental technique. A number of such visual sensors including carbon dots (CDs) have been reported for selective detection of many ionic and molecular species. This review elaborates the utilization of CDs as colorimetric sensors. Carbon dots (CDs) are being synthesized from a large number of natural and synthetic carbon source materials using a variety of methods. CDs can also be tuned chemically by doping, to impart the desired sensing properties. Therefore, the development of CDs with selective sensing properties enables extremely low detection limits and has thus gained substantial attention.

Nonenzymatic Electrochemical Detection of 2,4,6-Trichlorophenol Using CuO/Nafion/GCE: A Practical Sensor for Environmental Toxicants.

2,4,6-Trichlorophenol (2,4,6 TCP) is one of the hazardous toxicants, which has severe impacts on the environment and human health. This study is designed to develop a highly sensitive and selective electrochemical sensor based on CuO nanostructures for the detection of 2,4,6 TCP. The CuO nanostructures were synthesized through an aqueous chemical growth method and characterized by versatile analytical techniques, for example, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, atomic force microscopy, energy-dispersive spectrometry, and X-ray diffraction. The characterization tools revealed a high crystalline nature, exceptional phase purity, nanoball morphology with an average size of around 18.7 nm for the CuO nanostructures. The synthesized material was used to modify a glassy carbon electrode (GCE) with the help of Nafion as a binder to improve its efficiency and sensitivity. The CuO/Nafion/GCE was proven to be a potential sensor for the determination of 2,4,6 TCP under optimized conditions at a scan rate of 70 mV/s, potential range of 0.1-1.0 V, and phosphate buffer of neutral pH as the supporting electrolyte. The linear range for 2,4,6 TCP was set from (1 to 120 µM) with a low limit of detection value calculated to be 0.046 µM. The developed sensor was effectively applied for water samples with acceptable recovery values from 95.9 to 100.6%.