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The Himalayan region has several freshwater resources, such as rivers, lakes, and wetlands. These freshwater resources have been adversely affected by environmental factors. Freshwater biological systems are defenseless against outcomes of environmental changes that might prompt the irreversible disintegration of these natural surroundings. The present study aimed to investigate the effect of biotic and abiotic factors on the Benthic macro-invertebrate assemblages of the Asan wetland, Dehradun in Garhwal Himalaya. A determination of the physico-chemical health status of the Asan wetland viz., electrical conductivity (EC), total dissolved solids (TDS), biochemical oxygen demand (BOD), and nutrients parameters like nitrogen, potassium, and phosphorus were investigated during this study. Three sampling sites (Site 1, Site 2 and Site 3) of wetland were selected and the water samples were collected seasonally, i.e., summer, winter, and monsoon from April 2021-March 2022. Maximum values of EC(163.75 µS/cm), TDS (232.78 (mg/l), alkalinity (141.20 mg/l) and pH(7.8) were recorded in the monsoon season (June-September) and minimum values of EC( 135.80µS/cm), TDS (196.80 (mg/l), alkalinity (119.80mg/l) and pH(7.2) were recorded in the winter season (November–February). An overall total of 18 macrobenthos genera belonging to four classes was identified. Maximum communities of macrobenthos were observed during the winter and minimum communities during the monsoon season. Canonical correspondence analysis (CCA) was used to determine whether microbenthic genera and habitat ecological parameters and showed a positive or negative correlation. Thus, the present study contributed to the status of various factors and their impacts on the Benthic macro-invertebrate structure of the Asan wetland.

'Tilletia indica', a fungal pathogen causes Karnal bunt disease in wheat. It has been renowned as a quarantine pest in more than 50 countries, therefore, urged a threat to wheat in the international market. To date, conventional methods employed to detect the disease involve the tentative identification of spores (teliospores) based on morphology. For effective and specific disease control, it is essential to get the specific protein of the analyte (teliospore) to target. In present study, a label-free immunosensor has been developed to detect Karnal bunt disease. A specifically synthesized anti-teliosporic monoclonal antibody (mAb) was immobilized on a self-assembled monolayer of 11-mercaptoundecanoic acid (11-MUA) to detect teliospore. All modified electrodes were morphologically characterized by scanning electron microscopy (SEM), atomic force microscopy(AFM), Fourier transform infra-red spectroscopy (FT-IR) techniques and analytically characterized by quartz crystal microbalance (QCM) and cyclic voltammetry (CV). The linearity range was 19 pg mL

The presence of mycotoxins in food materials is difficult to control, and some mycotoxins are carcinogenic even at very low concentration. Therefore, there is a demand for fast, sensitive, user friendly, and stable method for the detection of mycotoxins. A portable smart biosensor is in a recent appeal in industries and daily life in place of tedious and time taking conventional techniques. In the present chapter, we analyze the current scenario for mycotoxin detection by immunosensors based on labeled and label-free methods, aptasensors. Some other recent trends such as mimotope and nanobody as a recognition agent for mycotoxin sensing are also discussed. We also discussed the new trends in nanomaterials, or matrix of electrode and transuding techniques. The current challenges, and technological aspects which experience during the development of biosensors are also discussed, at the end future research aspects mentioned.

Background To analyze the epidemiology of hospitalized ocular injuries occurring in counter insurgency and proxy war environment in a forward area of northern India over a period of 13 years. Methods Retrospective observational study of medical records was performed of 458 patients with ocular injuries primarily treated at zonal referral hospital of Indian Army between January 1992 and December 2004. Results A total of 559 eyes with ocular injuries were studied. The average age of the victims was 30 years. In 77% cases, injuries were sustained by army personnel and remaining by paramilitary forces. Of all cases, 86.5% cases were due to combat-related (militant action), of which 93.9% cases were caused by splinters from munitions. Among the eyes injured due to militant action, 60.36% were open globe injuries, 31.19% were closed globe injuries and 8.45% were isolated adnexal injuries. Among the eyes injured, 76.33% of the eyes with open globe injuries owing to militant action had perforating injuries, whereas in closed globe injuries, 47.74% eyes had corneal foreign body. Among eyes with open globe injuries, Corneo-scleral, scleral and corneal lacerations were seen in 45%, 28% and 27% eyes respectively. 15.75% of eyes with ocular injuries underwent eviscerations. Conclusion The study reveals that splinter eye injuries from munitions were the most common cause of ocular morbidity in counter insurgency and proxy war. Implementation of use of protective glasses by the personnel deployed in such hostile environment and strict compliance of preventive measures would be effective in saving eyes and also medical and economic resources.

This paper explains all the chances of environmental biotechnology techniques useful in aquaculture and reviews its various areas together. Biotechnology has played a vital role in boosting production in the aquaculture sector. Considering the number of issues which deteriorate the ecological conditions in an aquaculture system, the field of environmental biotechnology has shown new possibilities to enhance the terms. Since the environment turns to be a vital segment in the survival of aquatic flora and fauna its day by day deterioration via pollution and toxic substances are need to be checked. The distinct role of environmental biotechnology within the sector of aquaculture emphasized finding the opportunities to contribute with new solutions and directions in remediating the contaminated environments, minimizing future waste release and creating pollution prevention alternatives.

Malaria is still a major disease in sub-Saharan Africa and South-East Asia. This is despite different interventions by the World Health Organization (WHO), such as insecticide-treated mosquito net, antimalarial drugs, indoor residual spraying, and rapid diagnostic tools. In 2018, the mortality rate due to malaria was estimated to be 405 000, with children under five years accounting for 67% of all malaria deaths. Malaria can be prevented and treated using different strategies as recommended by WHO. However, the lack of rapid diagnostic tools with good selectivity and sensitivity is still a challenge. Therefore there is a need to develop rapid, low-cost, and portable analytical methods for quantifying malaria. This review focuses on the role of malaria biomarkers (Plasmodium falciparum Lactate Dehydrogenase (PfLDH), Plasmodium aldolase, Plasmodium falciparum Histidine-Rich Protein 2 (PfHRP2), Plasmodium falciparum Glutamate dehydrogenase (PfGDH), and Hemozoin) in diagnosis. Recent developments in nanomaterial-based electrochemical and colorimetric biosensors for malaria diagnosis are discussed. Finally, the review concludes with closing remarks and future perspectives of electrochemical biosensors.

This study emphases on electrochemical detection of ciprofloxacin in sheep serum and runoff water using silver nanoparticle modified β-cyclodextrin (Ag-β-CD) composite. The Ag-β-CD composite was synthesized via a hydrothermal route, which resulted in a high product yield. Morphological and spectral characterizations of the Ag-β-CD composite were carried out. The Ag-β-CD composite was used to detect ciprofloxacin by employing differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The Ag-β-CD modified electrode displayed excellent specificity towards the electro-oxidation of ciprofloxacin. Further, the sensor gave the best response towards the electro-oxidation of ciprofloxacin near the human physiological pH of 7.5. A linear response was obtained between the concentration range of 0.1 nM to 50 nM and the limit of detection (LOD) at 0.028 nM with high sensitivity and selectivity towards ciprofloxacin oxidation. The current work has a rationally synthesized and characterized nanocomposite with a very high potential for rapid and sensitive detection of ciprofloxacin in spiked sheep blood serum and domestic runoff water samples. High sensitivity and low LOD results illustrate good practicability for the detection of ciprofloxacin in such samples in the near future.

A series of Bi 1-x Sr x FeO 3 (x = 0.1, 0.2, 0.3, 0.4 and 0.5) multiferroic samples have been prepared using rapid two stage solid state reaction method in order to study the effect of different concentrations of strontium on the crystal structure, dielectric and magnetic properties. Structural analysis has been performed using x-ray diffraction (XRD) measurements. Rietveld refined XRD data confirms that all the samples are of single phase, having hexagonal structure with R 3 c space group. Unit cell volume decreases with increase in Sr 2+ concentration. Dielectric measurements have been performed in the temperature range of 295–520 K at selected frequencies in the range 100–900 kHz which show weak frequency dispersion. Activation energies are calculated for all the samples. Considerable enhancement in magnetic properties has been observed particularly for 40% and 50% doped samples. Further, exchange bias in hysteresis loop of 50% doped sample has also been observed.

The Clediocranial dysplasia is a dominant autosomal inheritance disease which is actually rare in occurrence. This has no race or gender predilection. Dental surgeons are usually the first professional to come across this disease, as patient first visit dentist with the chief complaint of missing teeth which is one of the most common clinical feature associated with this . In this series also the patient reposted to us with the chief complain of missing teeth. In this article we are presenting one case of patient with Clediocranial dysplasia.

Multiwall carbon nanotubes incorporated with iron oxide nanoparticles (MWCNTs-iron oxide) were prepared using a cheap, facile in-situ flame synthesis method. The nanocomposites were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray powder diffractometry, and Raman spectroscopy. MWCNTs-iron oxide nanocomposite was used to fabricate a sensitive electrochemical sensor for the detection and quantification of proguanil. The fabrication of the sensor was done by modifying a glassy carbon electrode with multiwall carbon nanotubes-iron oxide nanocomposite (MWCNTs-iron oxide). Differential pulse voltammetry (DPV) and cyclic voltammetry (CV) were used to study the electrochemical oxidation of proguanil. The selectivity of the sensor was investigated in the presence of organic and inorganic interfering agents. Furthermore, spiked human urine samples and pharmaceutical formulation were used to evaluate the utility of the sensor. A detection limit of 1.96 × 10−8 M was obtained under optimum conditions. MWCNTs-iron oxide nanocomposite can, therefore, be used to fabricate electrochemical sensors for quality control purposes.

Quality control of antimalarial drugs is essential due to the prevalence of counterfeit medicines. In this work, polyaniline-cobalt oxide nanofibers were synthesized using precipitation oxidation and interfacial polymerization. The nanocomposites were characterized using UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Morphological studies confirmed the formation of PANI nanofibers. The presence of Co3O4 in the composite was confirmed by XRD and EDX. Differential pulse voltammetry (DPV) and cyclic voltammetry (CV) were used to study the simultaneous electrochemical detection of primaquine and proguanil using a glassy carbon electrode modified with polyaniline nanofibers incorporated with cobalt oxide nanoparticles (PANI-Co3O4/GCE). The optimum pH for the response of the sensor was found to be 3.5 for both drugs. A limit of detection (LOD) of 2.07 nM and 1.42 nM with a linear range of 0.020–0.036 and 0.016–0.028 mM was obtained for primaquine and proguanil, respectively. Additionally, the practical applicability of PANI-Co3O4/GCE was studied in human urine with different interfering agents, good recovery of both drugs ranging within 94–105% was achieved. PANI-Co3O4 nanocomposite can therefore be used to fabricate electrochemical sensors for quality control purposes.

An economical and reliable theranostic unit is essential for the detection and treatment of bacterial infections. MRSA is one of the most prevalent superbugs in the world at present, hence requires urgent attention. Here, we present a novel copper-based 3-D porous nanocomposite modified with vancomycin (Van) for simultaneous detection and treatment of methicillin-resistant S. aureus (MRSA). The composite contains copper/copper oxide nanoparticles which are reduced by the hydroxyl groups of β-cyclodextrin (β-CD). On addition of graphene oxide (GO), it achieves a porous structure due to π-π stacking and formation of hydrogen bonds between β-cyclodextrin (β-CD) and reduced graphene oxide sheets. Conjugation of Van to the composite provides highly specific binding towards gram-positive bacteria. Differential pulse voltammetry (DPV) was used to carry out the electrochemical detection of MRSA and achieved a very low limit of detection (LOD) 5 CFU mL−1 along with a minimum inhibitory concentration (MIC) value of 1.93 μg mL−1. The low LOD and MIC values are due to the good electrochemical response of the composite and the synergetic antibacterial effect of vancomycin and copper/copper oxide nanoparticles, respectively. The current work provides a more effective and economic unit as electrode modifier simultaneous detection and powder for the elimination of pathogenic bacteria.

In this study, a novel sensor for highly selective and rapid detection of ciprofloxacin is fabricated. A facile strategy was employed to fabricate the electrode by electro-polymerization of phenol red (PPR) followed by drop-casting of reduced graphene oxide (rGO). Under optimized experimental conditions, the developed electrode shows, two linear ranges 0.002–0.05 μM and 0.05–400 μM, and the sensitivities equal to 516.41 μA μM−1 cm−2 and 0.239 μA μM−1 cm−2, respectively for ciprofloxacin detection. The rGO/PPR/GCE electrode enhanced sensitivity and low detection limit (LOD) (2 nM) of ciprofloxacin due to selective adsorption, which is accomplished by a combination of electrostatic attraction at SO3¯ sites in the PPR film, and the formation of charge assisted hydrogen bonding between ciprofloxacin and rGO surface functional groups. The novel nanocomposite was characterized by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), cyclic voltammetry (CV) and electrical impedance spectroscopy (EIS). Differential pulse voltammetry (DPV) was used to study the response of ciprofloxacin towards the modified electrode. The composite modified electrode displayed good electro-catalytic activity towards the oxidation of ciprofloxacin at pH 5.5 and exhibited high sensitivity and specificity towards ciprofloxacin. The practical applicability was tested in the spiked animal serum sample. The recovery of analytes in spiked samples was 97 ± 6% over the range 0.002–400 μML−1. It shows that the developed electrode can be used as a potential tool for a rapid, simple, and sensitive detection of ciprofloxacin in the serum sample.

Recently, increased attention has been drawn to application of graphene and its derivatives for construction of biosensors, since they can be used to rapidly detect the presence of bio-analytes. Present paper establishes the preparation of a unique transducer which relies on toluidine blue (TB), absorbed by electrochemically reduced graphene oxide (ERGO) transparent thin film onto the surface of the indium tin-oxide (ITO) glass electrode. The proposed TB/ERGO/ITO electrode shows excellent reversible electro-chemical properties. The novel platform has been explored to fabricate a triglyceride (TG) biosensor via co-immobilizing of lipase (LIP) and glycerol dehydrogenase (GDH) onto TB/ERGO/ITO electrode surface. The fabricated bioelectrode (LIP-GDH/TB/ERGO/ITO) directly oxidizes glycerol (produced by catalytic hydrolysis of tributyrin acting as a model TG) in the presence of GDH. The developed bioelectrode replaces unstable biological irreversible redox mediators NAD+/NADH, involved in the triglyceride breakdown reaction. NADH causes fouling on the bioelectrode surface in bi-enzymatic estimation of TG and reduces the shelf-life of biosensor. Electrochemical response studies carried out using cyclic voltammetry reveal that the fabricated electrode can detect tributyrin in the range of 50-400 mg dL-1 with high sensitivity of 29 pA mg-1 dL, low response time of 12 s, long-term stability and a low apparent Michaelis-Menten constant (Kappm) of 0.18 mM, indicating high enzyme affinity of LIP-GDH/TB/ERGO/ITO bioelectrode towards tributyrin. Furthermore, this modified bioelectrode has been explored for estimation of TG with negligible interference in human serum samples. The proposed bi-enzymatic bioelectrode for TG analysis offers an efficient and novel interface for application of graphene and its derivatives in the field of bioelectronic devices.

A competitive, reusable, reliable and sensitive immunosensor based on electrochemical quartz crystal microbalance (EQCM) was developed for the detection of aflatoxin B1 (AFB1). The sensing platform was developed using a primary monoclonal anti-aflatoxin antibody (anti AFB1) covalently immobilized on a monolayer of 4-amino thiophenol self assembled on a gold coated quartz crystal electrode (anti AFB1/4-ATP/Au). The reusability was achieved by a sandwiched system using secondary rabbit-immunoglobulin antibodies (r-IgGs) tagged with core shell of gold coated iron oxide nanoparticles (r-IgG–Au-Fe3O4), which can be used to regenerate the bioelectrode. A competitive mode was employed, between free and coated AFB1 for fixed concentration of nanoparticle conjugate (r-IgG–Au–Fe3O4). After the competitive interaction, immunoelectrode was washed with phosphate saline buffer (PBS) at pH 7.4 and examined by electrochemical quartz crystal microbalance-cyclic voltammetry (EQCM-CV). Under the optimized conditions, the fabricated immunosensor can be used to detect AFB1 quantitatively with a linear range of 0.05 to 5 ng mL−1. For reliability, the fabricated immuno sensor was tested using cereal samples spiked with different concentrations of AFB1. In addition, this immuno electrode displays good reproducibility, and storage stability. The above immunosensor was regenerated with negligible loss in activity through removal of the r-IgG–Au–Fe3O4 conjugate using a strong magnet. It is shown that theAFB1/BSA/aAFB1/4-ATP/Au immuno sensor is a new approach for developing sensitive reliable and reusable electrochemical piezoelectric immunosensors.

An electrochemical quartz crystal microbalance (EQCM) based label-free immunosensor has been developed for the quantitative detection of aflatoxin B1 (AFB1) in groundnut. The gold (Au) coated quartz crystal (6 MHz) functionalized with self-assembled monolayer (SAM) of 4-aminothiophenol (4-ATP) has been utilized to immobilize anti-aflatoxin antibodies (aAFB1). The quartz crystal microbalance QCM frequency and EQCM cyclic voltammetry measurements have been used to optimize the deposition of SAM layer on Au electrode (4-ATP/Au), antibody immobilization (aAFB1/4-ATP/Au), bovin serum albumin (BSA) adsorption (BSA/aAFB1/4-ATP/Au) and immuno interaction (AFB1/BSA/aAFB1/4-ATP/Au). Interestingly, the EQCM studies conducted on this immunoelectrode provide wider linear range of 0.1–4.0 ng mL −1 and higher sensitivity than those obtained using under identical condition. The high association constant of 9.4 × 10 −2 ng mL −1 of the EQCM immunosensor can be attributed to molecularly oriented self assembled monolayer of 4-ATP on QCM gold electrode that acts as a nanowire between aAFB1 and electrode through amide linkage formed by the NH 2 group of 4-ATP and COOH group of Fc part of aAFB1. This linkage also helps to project paratope part of aAFB1 to interact with AFB1. The developed label free EQCM based immunosensor was tested for the AFB1 detection in the extract of contaminated groundnut and the results were compared with Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The comparative results demonstrate the suitability of this sensor for routine screening of groundnut and the percent error is found to be ±12%.

A novel mediatorless reusable glucose biosensor with a remarkable shelf life has been fabricated on electrodeposited film of chemically synthesized nanostructured polyaniline (NSPANI) on indium tin oxide (ITO) coated glass plates using cyclic voltammetry. Glucose oxidase has been covalently immobilized on electrodeposited NSPANI film to fabricate a glucose bioelectrode (GOx/NSPANI-SDS/ITO). The results of linear sweep voltammetry and the high value of heterogeneous rate constant as obtained using Laviron equation indicates that GOx/NSPANI-SDS/ITO bioelectrode can detect glucose in the range of 0.5 to 10.00 mM with high sensitivity of 13.9 μA?mM?1 with a fast response time of 12 seconds. The linear regression analysis of bioelectrode reveals standard deviation and correlation coefficient of 6 μA and 0.994, respectively. The low value of Michaelis-Menten constant (Km) estimated as 0.28 mM using Lineweaver-Burke plot indicates high affinity of glucose oxidase enzyme to glucose and transfer rate. The GOx/NSPANI-SDS/ITO bioelectrode exhibits uniform activity for 12 weeks under refrigerated conditions; however the study is further going on. Attempts have been made to utilize this electrode for estimation of glucose in blood serum and results are found to be within 11% error. The unique features of this novel electrode lie on its reusability, real time monitoring, reproducibility and remarkable shelf life apart from the wide linear range, high sensitivity, low Km value, high heterogeneous electron-transfer constant etc.

A novel impedimetric biosensor was fabricated for total cholesterol sensing based on platinum nanoparticle and polypyrrole multilayer nanocomposite electrode. The Pt nanoparticles (PtNP) electrochemically deposited between two polypyrrole layers on indium tin oxide (ITO) glass plates (PtNP/PPY/ITO) have offered high-electroactive surface area and favourable microenvironment for immobilization of cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) resulting in enhanced electron transfer between the enzyme system and the electrode. Impedimetric response studies of the ChEt-ChOx/PtNP/ITO nanobioelectrode exhibit improved linearity (2.5 × 10-4 to 6.5 × 10-3 M/l), low detection limit (2.5 × 10-4 M/l), fast response time (25 s), high sensitivity (196 Ω/mM/cm-2) and a low value of the Michaelis-Menten constant (Km, 0.2 M/l) with a regression coefficient of 0.997.

A novel nanobiocomposite bienzymatic amperometric cholesterol biosensor, coupled with cholesterol oxidase (ChOx) and horseradish peroxidase (HRP), was developed based on the gold-nanoparticle decorated graphene-nanostructured polyaniline nanocomposite (NSPANI-AuNP-GR) film which was electrochemically deposited onto indium-tin-oxide (ITO) electrode from the nanocomposite (NSPANI-AuNP-GR) dispersion, as synthesized by in situ polymerization technique. The gold nanoparticle-decorated graphene-nanostructured polyaniline nanocomposite (NSPANI-AuNP-GR) offers an efficient electron transfer between underlining electrode and enzyme active center. The bienzymatic nanocomposite bioelectrodes ChOx-HRP/NSPANI-AuNP-GR/ITO have exhibited higher sensitivity, linearity, and lower Km value than monoenzymatic bioelectrode (ChOx/NSPANI-AuNP-GR/ITO). It is inferred that bienzyme-based nanobioelectrodes offer wider linearity (35 to 500 mg/dL), higher sensitivity (0.42 μAmM−1), low km value of 0.01 mM and higher accuracy for testing of blood serum samples than monoenzyme system. Mechanism of the overall biochemical reaction has been proposed to illustrate the enhanced biosensing performance of the bienzyme system. The novelty of the electrode lies on reusability, extended shelf life, and accuracy of testing blood serum samples.

In this study, glucose and hydrogen peroxide (H2O2) biosensors based on nanostructured conducting polyaniline (NSPANI) (synthesized using sodiumdodecyl sulphate (SDS) as structure directing agent) were developed. Because of the large specific surface area, excellent conductivity of NSPANI, horseradish peroxidase (HRP) and glucose oxidase (GOx) could be easily immobilized with high loading and activity. In addition the small dimensions and the high surface-to-volume ratio of the NSCP allow the rapid transmission of electron and enhance current response. The linear dynamic range of optical glucose and H2O2 biosensors is 5–40 mM for glucose and 1–50 mM for H2O2, respectively where as the bulk PANI exhibits linearity between 5-20 mM/l. The miniature optical glucose biosensor also exhibits good reproducibility. The storage stability of optical glucose and H2O2 biosensors is two weeks for glucose and five days for H2O2. The high response value of NSPANI based biosensors as compared to bulk PANI based biosensor reflects higher enzymatic affinity of GOx/NSPANI and HRP/NSPANI with glucose and H2O2 due to biocompatibility, active surface area and high electron communication capability of nanobiopolymer film. In conclusion, the NSPANI based biosensors proposed herein have many advantages such as a low response time, high reproducibility, high sensitivity, stable and wide dynamic range.

A label-free electrochemical quartz crystal microbalance (EQCM) based immunosensor using self-assembled monolayer of hexandithiol (HDT), cysteamine and 3D gold nanoparticles (AuNPs) was fabricated and utilized for aflatoxin B1 (AFB1, food mycotoxin) detection. The morphology, bonding and optimized experimental conditions of fabricated electrode and immunoelectrode were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR) and electrochemical quartz crystal microbalance cyclic voltammetry (EQCM-CV) techniques. This novel Cys/AuNPs/HDT/Au platform was utilized for covalent immobilization of aAFB1. The two linear ranges are observed under optimized experimental conditions i.e. 0.008–0.3 ng mL −1 and 1–10 ng mL −1 that can be used to estimate AFB1 with high sensitivity of 126 μA ng −1 mL cm −2 and low detection limit of 8 pg mL −1 using EQCM-CV. The label free AFB1 detection in noncompetitive mode with high sensitivity and wide linear range is assigned to the presence of antibodies and networking of 3D AuNPs on self assembled HDT monolayer. Attempts have also been made to utilize the immnunosensor for detection of AFB1 in spiked corn flakes samples for validating the observed results.

A quick and convenient method has been developed for the micro estimation of antihistamine drugs. 15 mg of sample is allowed to react with 10 ml of 0.02 M, N-bromosaccharin solution. Unconsumed reagent can

A simple, quick and convenient method has been developed for the micro estimation of S- containing amino acids. The sample 1-5 mg is allowed to react with 2 ml of 0.3N ammonium metavanadate (v) reagent and 10 ml of 10N H2SO4 was added, before the reaction helps in detecting the end point. The unconsumed reagent can be accurately titrate with 0.025 N ferrous ammonium sulphate solution using N-phenyl anthranilic acid as indicator. Standard deviation as well as coefficient of variation was calculated for reproducible and accurate result. The accuracy of the method in within + 1%

A reusable sandwiched electrochemical piezoelectric immunosensor has been developed for aflatoxin B1 (AFB1) detection using gold coated iron oxide core-shell (Au-Fe3O4) nanostructure. The monoclonal anti-aflatoxin antibody (aAFB1) was immobilized on self-assembled monolayer of 4-aminothiophenol on gold coated quartz crystal to fabricate immunoelectrode (BSA/aAFB1/4-ATP/Au). In addition, secondary rabbit-immunoglobulin antibodies (r-IgGs) functionalized with Au-Fe3O4NPs via cysteamine (r-IgG-Cys-Au-Fe3O4) were allowed to interact with AFB1. Both competitive and noncompetitive strategies were employed and a competition between coated AFB1 and free AFB1 was carried out. The competitive mode shows higher linear range (0.05 to 5 ng mL−1) than the noncompetitive one (0.5 to 5 ng mL−1), high sensitivity 335.7 µA ng−1 mL cm−2, and LOD 0.07 ng mL−1. The fabricated immunosensor has been tested using cereal samples spiked with different concentrations of AFB1. The developed competitive immunoelectrode displays good reproducibility, and storage stability and regenerated with negligible loss in activity through removal of the r-IgG-Cys-Au-Fe3O4conjugate using a strong external magnet.

A novel amperometric glucose biosensor based on bienzyme system such as glucose oxidase (GOx) and horseradish peroxidase (HRP) was developed based on the carboxy modified multiwalled carbon nanotubes (MWCNT) and polypyrrole (PPY) nanocomposite film, electrochemically deposited onto indium-tin-oxide (ITO) electrode using layer by layer deposition technique. The glucose oxidase (GOx) and horseradish peroxidase (HRP) have been coimmobilized onto the MWCNT/PPY/ITO nanocomposite electrode using gluteraldehyde as a crosslinking agent. The bienzymatic nanobioelectrodes GOx-HRP/MWCNT/PPY/ITO have exhibited 3 times higher sensitivity than mono enzymatic bioelectrode (GOx-HRP/MWCNT/PPY/ITO). Minimum interferences have been observed from ascorbic acid, uric acid, sodium pyruvate, and sodium ascorbate for both single and bienzyme systems. It is inferred that bienzyme-based nanobioelectrodes offer wider linearity, higher sensitivity, correlation coefficient, shelf life, and accuracy for testing of blood serum samples than mono enzyme system. Mechanism of the overall biochemical reaction has been proposed to illustrate the enhanced bio-sensing performance of the bienzyme system. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

The present paper reports synthesis, characterization, spectrophotometric studies and activity prediction of HPMPT with Fe (III) complexes. It was observed that Fe (III) forms complex with HPMPT in 1:3 ratio at wavelength of 510 nm and between the pH range of 4.3–4.8. The molar absorptive and Sandell's sensitivity values are 52175 L mol−1 cm−1 and 1.32 ng cm−2 respectively. The study shows that metal chelates are better in activity as compared to their respective ligands. The results have been interpreted in terms of tables, figures and theories.

A novel amperometric cholesterol biosensor based on bienzyme system such as cholesterol oxidase (ChOx) and horseradish peroxidase (HRP) was developed based on the gold nanoparticles decorated graphene-nanostructured polyaniline nanocomposite (NSPANI/AuNP/GR) film, electrochemically deposited onto indium-tin-oxide (ITO) electrode. The cholesterol oxidase (ChOx) and horseradish peroxidase (HRP) have been coimmobilised onto the NSPANI/AuNP/GR nanocomposite electrode using gluteraldehyde as a crosslinking agent. The nanobioelectrodes ChOx-HRP/NSPANI/AuNP/GR/ITO and ChOx-/NSPANI/AuNP/GR/ITO have been characterised by differential pulse voltammetery (DPV), cyclic voltammetry (CV) and scanning electron microscopy (SEM). The bienzymatic nanobioelectrodes ChOx-HRP/NSPANI/AuNP/GR/ITO have exhibited higher sensitivity than mono enzymatic bioelectrode (ChOx-/NSPANI/AuNP/GR/ITO). Minimum interferences have been observed from ascorbic acid, uric acid, sodium pyruvate, glucose and urea for both single and bienzyme systems. It is inferred that bienzyme based nanobioelectrodes offer wider linearity (35 to 500 mg/dl), higher sensitivity (4.22 mAmM-1), high shelf life (8 weeks), low response time (19s) and high accuracy for testing of blood serum samples than mono enzyme system. Mechanism of the overall biochemical reaction has been proposed to illustrate the enhanced bio-sensing performance of the bienzyme system.