We report herein a flexible fluorescent nanofibrous membrane (FNFM) prepared by decorating the go... more We report herein a flexible fluorescent nanofibrous membrane (FNFM) prepared by decorating the gold nanocluster (AuNC) on electrospun polysulfone nanofibrous membrane for rapid visual colorimetric detection of H2O2. The provision of AuNC coupled to NFM has proven to be advantageous for facile and quick visualization of the obtained results, permitting instant, selective, and on-site detection. We strongly suggest that the fast response time is ascribed to the enhanced probabilities of interaction with AuNC located at the surface of NF. It has been observed that the color change from red to blue is dependent on the concentration, which is exclusively selective for hydrogen peroxide. The detection limit has been found to be 500 nM using confocal laser scanning microscope (CLSM), visually recognizable with good accuracy and stability. A systematic comparison was performed between the sensing performance of FNFM and AuNC solution. The underlying sensing mechanism is demonstrated using UV spectra, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The corresponding disappearance of the characteristic emissions of gold nanoclusters and the emergence of a localized surface plasmon resonance (LSPR) band, stressing this unique characteristic of gold nanoparticles. Hence, it is evident that the conversion of nanoparticles from nanoclusters has taken place in the presence of H2O2. Our work here has paved a new path for the detection of bioanalytes, highlighting the merits of rapid readout, sensitivity, and user-friendliness. Graphical Abstract Rapid visual colorimetric detection of H2O2.
The worldwide increase in the number of people suffering from diabetes has been the driving force... more The worldwide increase in the number of people suffering from diabetes has been the driving force for the development of glucose sensors. The recent past has devised various approaches to formulate glucose sensors using various nanostructure materials. This review presents a combined survey of these various approaches, with emphasis on the current progress in the use of electrospun nanofibers and their composites. Outstanding characteristics of electrospun nanofibers, including high surface area, porosity, flexibility, cost effectiveness, and portable nature, make them a good choice for sensor applications. Particularly, their nature of possessing a high surface area makes them the right fit for large immobilization sites, resulting in increased interaction with analytes. Thus, these electrospun nanofiber-based glucose sensors present a number of advantages, including increased life time, which is greatly needed for practical applications. Taking all these facts into consideration, we have highlighted the latest significant developments in the field of glucose sensors across diverse approaches.
Here, a distinct demonstration of highly sensitive and selective detection of copper (Cu(2+)) in ... more Here, a distinct demonstration of highly sensitive and selective detection of copper (Cu(2+)) in a vastly porous cellulose acetate fibers (pCAF) has been carried out using dithiothreitol capped gold nanocluster (DTT.AuNC) as fluorescent probe. A careful optimization of all potential factors affecting the performance of the probe for effective detection of Cu(2+) were studied and the resultant sensor strip exhibiting unique features including high stability, retained parent fluorescence nature and reproducibility. The visual colorimetric detection of Cu(2+) in water, presenting the selective sensing performance towards Cu(2+) ions over Zn(2+), Cd(2+) and Hg(2+) under UV light in naked eye, contrast to other metal ions that didn't significantly produce such a change. The comparative sensing performance of DTT.AuNC@pCAF, keeping the nonporous CA fiber (DTT.AuNC@nCAF) as a support matrix has been demonstrated. The resulting weak response of DTT.AuNC@nCAF denotes the lack of ligand protection leading to the poor coordination ability with Cu(2+). The determined detection limit (50 ppb) is far lower than the maximum level of Cu(2+) in drinking water (1.3 ppm) set by U.S. Environmental Protection Agency (EPA). An interesting find from this study has been the specific oxidation nature between Cu(2+) and DTT.AuNC, offering solid evidence for selective sensors.
... Ojas Mahapatra2, Shivaraman Ramaswamy2, N. Satya Vijaya Kumar, B. Brabu, Angeline Littleflowe... more ... Ojas Mahapatra2, Shivaraman Ramaswamy2, N. Satya Vijaya Kumar, B. Brabu, Angeline Littleflower, and C. Gopalakrishnan Nanotechnology Research Center, SRM University Kattankulathur, Tamil Nadu, 603203 India e mail: shivi ... Sun, B., Snaith, HJ, Dhoot, A., et al., J. ...
ABSTRACT Here we report, the preparation of flexible free standing Fibrous Composite Membrane (FC... more ABSTRACT Here we report, the preparation of flexible free standing Fibrous Composite Membrane (FCM) of PVA-ZnO by combined sol–gel and Electrospinning method. The morphology of the sample was investigated by SEM and TEM which confirmed the uniform distribution of ZnO on the surface of the fiber without much of aggregation. The high purity of the sample was proven by photoluminescence studies. Evaluation of antibacterial properties of the sample against both Gram-positive and Gram-negative bacteria, showed that the prepared sample by this method is most effective for Methicillin-resistant Staphylococcus aureus. The mechanism responsible for the bactericidal effect of ZnO has been discussed. The unique properties of the FCM would be highly significant for applications in antimicrobial coatings, UV sensors etc.
We report herein a flexible fluorescent nanofibrous membrane (FNFM) prepared by decorating the go... more We report herein a flexible fluorescent nanofibrous membrane (FNFM) prepared by decorating the gold nanocluster (AuNC) on electrospun polysulfone nanofibrous membrane for rapid visual colorimetric detection of H2O2. The provision of AuNC coupled to NFM has proven to be advantageous for facile and quick visualization of the obtained results, permitting instant, selective, and on-site detection. We strongly suggest that the fast response time is ascribed to the enhanced probabilities of interaction with AuNC located at the surface of NF. It has been observed that the color change from red to blue is dependent on the concentration, which is exclusively selective for hydrogen peroxide. The detection limit has been found to be 500 nM using confocal laser scanning microscope (CLSM), visually recognizable with good accuracy and stability. A systematic comparison was performed between the sensing performance of FNFM and AuNC solution. The underlying sensing mechanism is demonstrated using UV spectra, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The corresponding disappearance of the characteristic emissions of gold nanoclusters and the emergence of a localized surface plasmon resonance (LSPR) band, stressing this unique characteristic of gold nanoparticles. Hence, it is evident that the conversion of nanoparticles from nanoclusters has taken place in the presence of H2O2. Our work here has paved a new path for the detection of bioanalytes, highlighting the merits of rapid readout, sensitivity, and user-friendliness. Graphical Abstract Rapid visual colorimetric detection of H2O2.
The worldwide increase in the number of people suffering from diabetes has been the driving force... more The worldwide increase in the number of people suffering from diabetes has been the driving force for the development of glucose sensors. The recent past has devised various approaches to formulate glucose sensors using various nanostructure materials. This review presents a combined survey of these various approaches, with emphasis on the current progress in the use of electrospun nanofibers and their composites. Outstanding characteristics of electrospun nanofibers, including high surface area, porosity, flexibility, cost effectiveness, and portable nature, make them a good choice for sensor applications. Particularly, their nature of possessing a high surface area makes them the right fit for large immobilization sites, resulting in increased interaction with analytes. Thus, these electrospun nanofiber-based glucose sensors present a number of advantages, including increased life time, which is greatly needed for practical applications. Taking all these facts into consideration, we have highlighted the latest significant developments in the field of glucose sensors across diverse approaches.
Here, a distinct demonstration of highly sensitive and selective detection of copper (Cu(2+)) in ... more Here, a distinct demonstration of highly sensitive and selective detection of copper (Cu(2+)) in a vastly porous cellulose acetate fibers (pCAF) has been carried out using dithiothreitol capped gold nanocluster (DTT.AuNC) as fluorescent probe. A careful optimization of all potential factors affecting the performance of the probe for effective detection of Cu(2+) were studied and the resultant sensor strip exhibiting unique features including high stability, retained parent fluorescence nature and reproducibility. The visual colorimetric detection of Cu(2+) in water, presenting the selective sensing performance towards Cu(2+) ions over Zn(2+), Cd(2+) and Hg(2+) under UV light in naked eye, contrast to other metal ions that didn't significantly produce such a change. The comparative sensing performance of DTT.AuNC@pCAF, keeping the nonporous CA fiber (DTT.AuNC@nCAF) as a support matrix has been demonstrated. The resulting weak response of DTT.AuNC@nCAF denotes the lack of ligand protection leading to the poor coordination ability with Cu(2+). The determined detection limit (50 ppb) is far lower than the maximum level of Cu(2+) in drinking water (1.3 ppm) set by U.S. Environmental Protection Agency (EPA). An interesting find from this study has been the specific oxidation nature between Cu(2+) and DTT.AuNC, offering solid evidence for selective sensors.
... Ojas Mahapatra2, Shivaraman Ramaswamy2, N. Satya Vijaya Kumar, B. Brabu, Angeline Littleflowe... more ... Ojas Mahapatra2, Shivaraman Ramaswamy2, N. Satya Vijaya Kumar, B. Brabu, Angeline Littleflower, and C. Gopalakrishnan Nanotechnology Research Center, SRM University Kattankulathur, Tamil Nadu, 603203 India e mail: shivi ... Sun, B., Snaith, HJ, Dhoot, A., et al., J. ...
ABSTRACT Here we report, the preparation of flexible free standing Fibrous Composite Membrane (FC... more ABSTRACT Here we report, the preparation of flexible free standing Fibrous Composite Membrane (FCM) of PVA-ZnO by combined sol–gel and Electrospinning method. The morphology of the sample was investigated by SEM and TEM which confirmed the uniform distribution of ZnO on the surface of the fiber without much of aggregation. The high purity of the sample was proven by photoluminescence studies. Evaluation of antibacterial properties of the sample against both Gram-positive and Gram-negative bacteria, showed that the prepared sample by this method is most effective for Methicillin-resistant Staphylococcus aureus. The mechanism responsible for the bactericidal effect of ZnO has been discussed. The unique properties of the FCM would be highly significant for applications in antimicrobial coatings, UV sensors etc.
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Papers by Brabu Balusamy