High-performance electrochemical sensing of hazardous pesticide Paraoxon using BiVO4 nano dendrites equipped catalytic strips.

Paraoxon is one of the pesticide that can induce toxicity to nervous system of living organisms. In this work, we focused on synthesizing the catalyst Bismuth Vanadate with the properties that can sense the presence of organophosphorus compounds and characterized them with various characterization methods. The structural studies done by XRD, UV spectroscopy and FTIR spectroscopy. Morphological studies were carried by SEM and TEM. Elemental analysis using XPS spectra. The proposed electrocatalyst was successfully applied as the active electrode material modifying the screen printed carbon electrode for electrochemical sensor applications. The results of the studies indicate that bismuth vanadate modified electrode exhibited four electron transfer process for reduction of nitro group and this lead to the superior electrochemical sensing performance for ethyl Paraoxon with a detection limit of 0.03 µM and good sensitivity 0.345 µA µM-1 cm-2 with excellent reproducibility, repeatability, stability and selectivity over common interferents. Furthermore, the practical application was successfully carried using the proposed modified strips to determine Paraoxon presence in the river water sample with satisfactory results. This proposed catalyst can act as a desirable candidate for the rapid electrochemical sensor.

Amperometric determination of ecotoxic N-methyl-p-aminophenol sulfate in photographic solution and river water samples based on graphene oxide/CeNbO4 nanocomposite catalyst.

The electronic conductivity of the metal oxides is generally increased by hybridization of highly conductive carbon supportive materials. In this present work, we have demonstrated a novel one-pot preparation of cerium niobate (CeNbO4) nanoparticles embedded with graphene oxide (GO/CeNbO4) composite, for ultrasensitive detection of the photographic developing agent, metol (MTL). The as-prepared GO/CeNbO4 was analyzed by various characterization techniques. The intensive characterization techniques were used to affirm the detailed structural moiety, size, morphology, and surface area of GO/CeNbO4. The GO/CeNbO4 modified glassy carbon electrode (GCE) affords a superior electrocatalytic activity toward MTL. The obtained amperometric response on the GO/CeNbO4/GCE holding an extremely low level detection of 10 nM and superior sensitivity of 10.97 µA µM-1 cm-2 toward MTL detection. Besides, the GO/CeNbO4/GCE also gives excellent selectivity, stability, repeatability, and reproducibility. We achieved excellent recovery results in real photographic solution and river water samples analysis with great accuracy. This work offers a novel insight into the growth of the carbon-based niobate family with electrochemical sensor applications.

Tailoring of bismuth vanadate impregnated on molybdenum/graphene oxide sheets for sensitive detection of environmental pollutants 2, 4, 6 trichlorophenol.

In the present work, we reported a one pot simple colloidal-gel synthesis of molybdenum bismuth vanadate (MoBiVO4). The charge transfer property of MoBiVO4 was improved by developing a composite with graphene oxide (GO) through sonochemical technique. The optical and morphological analysis revealed that successful formation of GO-MoBiVO4 composite without any other filth. As prepared composite was used to modify the superficial surface of glassy carbon electrode (GO-MoBiVO4/GCE) and applied for the selective detection of environmental pollutant 2, 4, 6 trichrlorophenol (TCP). The electron channeling capability of GO with molybdenum bismuth vanadate possessed a superior electrochemical response in cyclic voltammetry (CV), whereas bare GCE and other modified electrodes provided an inferior response with lower current response. The differential pulse voltammetry (DPV) response of TCP at GO-MoBiVO4/GCE outcomes with low level detection of 0.4 nM and higher sensitivity of 2.49 µA µM-1 cm-2 with wider linear response 0.199-17.83 µM. Furthermore, the proposed sensor applied in practicability analysis and the results indicates GO-MoBiVO4/GCE prominent towards electrochemical detection of TCP.

Electrochemical sensing base for hazardous herbicide aclonifen using gadolinium niobate (GdNbO4) nanoparticles-actual river water and soil sample analysis.

The present work scrutinized the voltammetric analysis of hazardous herbicide aclonifen (ACF) in actual soil and river water samples utilizing the electrochemical method. The electrochemical sensing device was fabricated for the determination of ACF using gadolinium niobate (GdNbO4) nanoparticles modified glassy carbon electrode (GCE). The novel GdNbO4 sensing material was prepared via a simple co-precipitation method. Several characterization techniques (TEM, EDS, XRD, XPS, and BET) were utilized to analyze the structural features of the GdNbO4. The enhanced electrochemical behavior of GdNbO4 modified GCE towards ACF was observed compared to bare GCE. The cyclic voltammetry response revealed that the prepared sensor shows the lower negative potential with a dramatic increase in the peak current of ACF compared to bare GCE. In the differential pulse voltammetry, the limit of detection (1.15 nM) and sensitivity (23 µA µM-1 cm-2) of the ACF on the GdNbO4 modified GCE was comparatively superior to the formerly proposed ACF based sensor. This sensor reveals good selectivity, repeatability, reproducibility, and long-term stability. The reliability of the sensor exhibits satisfactory recovery results for ACF detection in river water and soil samples.

Unicentric Castleman's Disease as a Localized Retroperitoneal Mass: A Case Report and Review of Literature.

Castleman's disease (CD) is a rare disorder characterized by proliferation of the lymphoid tissue. Clinically, it presents in two forms either a unicentric (UC) or multicentric. Mediastinum is the most common location. UC retroperitoneal presentation is rare. We report a case of 29-year-old female who presented with left loin pain, and on abdominal imaging, evaluation identified a retroperitoneal mass in the left hypochondrium in the pararenal space. Mass was surgically excised entirely. Histopathological examination demonstrated hyaline vascular type of CD. CD should be considered in differential diagnosis of retroperitoneal mass, especially in equivocal cases. We also reviewed literature of 134 cases of retroperitoneal CD to analyze the presentation, management, and outcome.

Spindle cell sarcoma of thyroid: a case report.

Spindle cell sarcoma of thyroid represents a rare entity that may arise primarily from thyroid gland as a variant of thyroid cancer or as metastatic. We report a case of 60 year old man who presented with 2 months history of rapidly growing thyroid enlargement with no obstructive features and preliminary diagnosis of spindle cell lesion of thyroid was made with cytological examination. He underwent total thyroidectomy and histological examination revealed spindle cell sarcoma of thyroid confirmed by immunohistochemical reactions. He was subjected to adjuvant chemoradiotherapy and is on follow up. Sarcoma of thyroid is rarely encountered in routine practice and is diagnosed by microscopic evaluation and immunohistochemical staining which determines the cellular origin and histologic type of tumor . Sarcoma thyroid is best managed with surgery and adjuvant chemoradiotherapy according to the grade of the lesion. In addition overall prognosis in thyroid sarcoma is poor due to late presentation and aggressive nature of the tumour.