Photocatalytic, fluorescent BiPO4@Graphene oxide based magnetic molecularly imprinted polymer for detection, removal and degradation of ciprofloxacin.

Herein, we have developed a photocatalytic, fluorescent bismuth phosphate@graphene oxide (BiPO4@GO) based magnetic nano-sized-molecularly imprinted polymer (MMIP) for detection, removal, and degradation of ciprofloxacin (CIP) via atom transfer radical polymerization (ATRP) process. CIP is a very popular antibiotic, but their heavy doses in recent time, made them an environmental threat. The imprinted polymer was synthesized using N-vinyl caprolactam, N, N-methylene bis-acrylamide, ZnFe2O4 nanoparticle, and Bi(PO4)@GO as a biocompatible monomer, crosslinker, magnetic moiety, and photocatalyst, respectively. The characterization of the molecularly imprinted polymer was systematically evaluated by electrochemical techniques, X-ray diffraction, fluorescence spectroscopy, scanning electron microscopy, etc. The prepared BiPO4@GO modified CIP-imprinted magnetic polymer (BiPO4@GO-MMIPs) shows high selectivity towards their template/target analyte (i.e., CIP) and used for their visual (via fluorescence study) and trace level detection (via the electrochemical study) in various kind of complex matrix. The dual behaviour i.e. electrochemical and optical sensing of CIP was successfully achieved in a good linear range of 39.0 to 740.0 µg L-1 with detection of limit (LOD) of 0.39 µg L-1 for electrochemical study and 39.0 to 328.0 µg L-1 and LOD of 0.40 µg L-1 for optical study. The prepared BiPO4@GO-MMIPs were successfully used for the detection of CIP from complex matrix like blood serum, whole blood, and milk sample as well as removal and degradation of CIP with good efficiency.

Retracted: Imprinted ZnO nanostructure-based electrochemical sensing of calcitonin: A clinical marker for medullary thyroid carcinoma.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor following concerns raised by various readers. The article reports different electron micrographs for different sample preparations, but some images are of different areas from the same sample. Figure 4E is a magnified section of Figure 4C, and the images are identical as demonstrated by overlapping the images and adjusting for magnification scale. The article reports EDX spectra in Figure 5C and Figure 5D for samples that are reported as different. An overlay of the spectra indicate they are identical in magnitude and in the random fluctuations of noise except in the specific zones where the signal was expected to vary. These problems with the data presented cast doubt on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Bismuth oxide decorated graphene oxide nanocomposites synthesized via sonochemical assisted hydrothermal method for adsorption of cationic organic dyes.

Bismuth oxide decorated graphene oxide (Bi2O3@GO) nanocomposites were successfully synthesized by sonochemical method followed by hydrothermal treatment. The structural, morphology/microstructure and functional groups were investigated through X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared (FTIR) spectroscopy, respectively. In the FESEM and TEM studies, well dispersed Bi2O3 nanoparticles of size 3-5nm were found uniformly distributed throughout the surface and edges of GO sheets. The HRTEM measurements on the Bi2O3 nanoparticle decorated graphene oxide shows imaged lattice spacing of 3.2Å corresponding to (111) plane of Bi2O3 which confirms the successful synthesis of bismuth oxide decorated graphene oxide (Bi2O3@GO) nanocomposite. The synthesized nanocomposite was employed for adsorption and removal of cationic organic dyes like RhB from industrial wastewater. The effect of various parameters, viz., contact time, temperature, pH and amount of adsorbent on the adsorption capability as well as dye removal capacity of the adsorbent was studied in detail. Under optimized conditions, like, contact time (65min), amount of adsorbent (5mg), temperature (35°) and pH (4), the adsorption capacity of GO and Bi2O3@GO were recorded and the percentage of removal was found to be 64% and 80.7% for GO and Bi2O3@GO, respectively. The Bi2O3@GO nanocomposite shows higher adsorption capacity (320mg/g) as compare to only GO (224mg/g). The adsorption isotherm follows both the Temkin as well as Langmuir isotherm having heat of sorption 65.88 with Langmuir constant of 13.13 corresponding to the complete monolayer coverage of 387.44mg/g. The adsorption kinetics also follow, both pseudo first order and intraparticle diffusion model with adsorption capacity of 84.91mg/g and intra particle diffusion rate constant of 10.53mg/g min1/2 for Bi2O3@GO nanocomposites. Our results suggest that the prepared Bi2O3@GO nanocomposites possess potential application as high-performance renewable adsorbent for removal of toxic dyes from wastewater.

RETRACTED: Anisotropic (spherical/hexagon/cube) silver nanoparticle embedded magnetic carbon nanosphere as platform for designing of tramadol imprinted polymer.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief following concerns raised by a reader. The particles shown in Fig. 3F appear to be copies of each other as they share the identical arrangement of the characteristic speckles inside the particles. In addition, the extraordinary similarities observed between the data presented in Fig. 4C and in Fig. 3C in ACS Biomater. Sci. Eng., 2017, 3 (9), pp 2120­2135, 10.1021/acsbiomaterials.7b00089, Fig. 4A in Colloids and Surfaces B: Biointerfaces, Volume 142, 1 June 2016, Pages 248-258 10.1016/j.colsurfb.2016.02.053 and Fig. 1D in Biosensors and Bioelectronics, Volume 73, 15 November 2015, Pages 234-244, 10.1016/j.bios.2015.06.005 are highly unlikely. The problems with the data presented cast doubt on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

RETRACTED: Designing of carbon based fluorescent nanosea-urchin via green-synthesis approach for live cell detection of zinc oxide nanoparticle.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of Editor following concerns raised by a reader. There are significant concerns regarding the originality of the electron micrographs displayed in Fig. 1 (panels B-G, especially C). The concern is that these multi-particle images are comprised of copies of the same particles. These problems with the data presented cast doubt on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process

Introduction of selectivity and specificity to graphene using an inimitable combination of molecular imprinting and nanotechnology.

Recently, the nanostructured modified molecularly imprinting polymer has created a great attention in research field due to its excellent properties such as high surface to volume ratio, low cost, and easy preparation/handling. Among the nanostructured materials, the carbonaceous material such as 'graphene' has attracted the tremendous attention of researchers owing to their fascinating electrical, thermal and physical properties. In this review article, we have tried to explore as well as compile the role of graphene-based nanomaterials in the fabrication of imprinted polymers. In other words, herein the recent efforts made to introduce selectivity in graphene-based nanomaterials were tried collected together. The major concern of this review article is focused on the sensing devices fabricated via a combination of graphene, graphene@nanoparticles, graphene@carbon nanotubes and molecularly imprinted polymers. Additionally, the combination of graphene and quantum dots was also included to explore the fluorescence properties of zero-band-gap graphene.

2-Dimensional graphene as a route for emergence of additional dimension nanomaterials.

Dimension has a different and impactful significance in the field of innovation, research and technologies. Starting from one-dimension, now, we all are moving towards 3-D visuals and try to do the things in this dimension. However, we still have some very innovative and widely applicable nanomaterials, which have tremendous potential in the form of 2-D only i.e. graphene. In this review, we have tried to incorporate the reported pathways used so far for modification of 2-D graphene sheets to make is three-dimensional. The modified graphene been applied in many fields like supercapacitors, sensors, catalysis, energy storage devices and many more. In addition, we have also incorporated the conversion of 2-D graphene to their various other dimensions like zero-, one- or three-dimensional nanostructures.

Single cell imprinting on the surface of Ag-ZnO bimetallic nanoparticle modified graphene oxide sheets for targeted detection, removal and photothermal killing of E. Coli.

A very cost-effective, fast, sensitive and specific imprinted polymer modified electrochemical sensor for the targeted detection, removal and destruction of Escherichia coli bacteria was developed onto the surface of Ag-ZnO bimetallic nanoparticle and graphene oxide nanocomposite. The nanocomposite played a dual role in this work, as a platform for imprinting of bacteria as well as a participated in their laser-light induced photo killing. In terms of sensing, our proposed sensor can detect E. Coli as few as 10CFUmL-1 and capture 98% of bacterial cells from their very high concentrated solution (105CFUmL-1). Similarly to the quantitative detection, we have also investigated the quantitative destruction of E. Coli and found that 16.0cm2 area of polymer modified glass plate is sufficient enough to kill 105CFUmL-1 in the small time span of 5 minutes. The obtained results suggest that our proposed sensor have potential to serve as a promising candidate for specific and quantitative detection, removal as well as the destruction of a variety of bacterial pathogens.

Anisotropic Gold Nanoparticle Decorated Magnetopolymersome: An Advanced Nanocarrier for Targeted Photothermal Therapy and Dual-Mode Responsive T1 MRI Imaging.

Herein, we report the advanced polymer vesicle [made up of triblock polymer: poly(ethylene oxide)-co-poly(Cys-AuNP@FA)-co-poly(3-methoxypropylacrylamide] having encapsulated magnetic nanoparticle capable of targeted methotrexate delivery (having folic acid as tagging agent), photothermal therapy [anisotropic gold nanoparticle (AuNPs)] and stimuli-responsive T1-imaging (as MRI contrast agent). The prepared polymersome, called as magnetopolymersome (MPS), after encapsulation of magnetic nanoparticle (Gd-doped) is not only high yield and simple in synthesis but also possess very high biocompatibility, more than 95% drug encapsulation efficiency and effective near-infrared (NIR) responsive photothermal therapy. The MPS is highly stable under normal physiological environments and other extreme end conditions (like presence of serum or Triton-X 100) and have excellent stimuli-responsive (temperature and NIR) T1-contrast effect in vitro conditions (60.57 mM-1 s-1). To explore the role of shape of AuNPs on the photothermal therapy and drug delivery behavior of prepared nanocarrier, herein, we have synthesized four different shapes of AuNPs, i.e., spherical, triangle, rod, and flower. It was found that nanoflower-conjugated MPS shows the most efficient NIR responsive behavior in comparison to their other colleagues, which broke the ancient myth that spherical nanoparticle are the best candidate for drug delivery process. These features make nanoflower or other anisotropic nanoparticle-based polymersome a very promising and efficient nanocarrier for drug loading, delivery, imaging, and photothermal therapy.