Browsing by Author "Amit Kumar Srivastava"

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A contemporary overview on quantum dots-based fluorescent biosensors: Exploring synthesis techniques, sensing mechanism and applications
(Elsevier B.V., 2025) Anushka Yadav; Priyanka Dogra; Pinky Sagar; Monika Srivastava; Amit Kumar Srivastava; Rajneesh Kumar; Sanjay Kumar Srivastava
In the epoch of bioinformatics, pivotal biomedical scrutiny and clinical diagnosis hinge upon the unfolding of highly efficacious biosensors for intricate and targeted identification of specific biomolecules. In pursuit of developing robust biosensors endowed with superior sensitivity, precise selectivity, rapid performance, and operational simplicity, semiconductor QDs have been acknowledged as pivotal and advantageous entities. In this review, we present a comprehensive analysis of the latest unfolding within the domain of QDs used in fluorescent biosensors for the detection of diverse biomolecular entities, encompassing proteins, nucleic acids, and a range of small molecules, with an emphasis on the synthesis methodologies of QDs employed and mechanism behind sensing. Additionally, this review delves into several pivotal facets of QD-based fluorescent biosensors in detail, such as surface functionalization methodologies aimed at enhancing biocompatibility and improving target specificity. The challenges and future perspectives of QD-based fluorescent biosensors are also considered, emphasizing the necessity of ongoing multidisciplinary research to realize their full potential in enhancing personalized medicine and biomedical diagnostics. © 2025 Elsevier B.V.
A smartphone-enabled colorimetric sensor based on VS2 quantum dots for Rapid and on-site detection of ferric ions
(Elsevier B.V., 2025) Anushka Yadav; Pinky Sagar; Monika Srivastava; Amit Kumar Srivastava; Rajneesh Kumar; Sanjay Kumar Srivastava
This research delves into the holistic hydrothermal synthesis of VS2 QDs and their subsequent utilization as a fluorescent probe for the subtle detection of ferric ions (Fe3+) in practical sample matrices. The detection paradigms harness a colorimetric sensing mechanism, amplified by smartphone-enabled analytical integration for improved precision and real-time monitoring. A comprehensive suite of analytical characterization techniques has been employed, revealing that the as-synthesized VS2 QDs feature a surface densely populated with functional groups. While the VS2 QDs showcase interactions with multifarious metal ions in aqueous media, they set forth a pronounced and selective fluorescent quenching response toward Fe3+ ions, markedly surpassing their interactions with other metal ions. The developed sensing probe exhibits a linear detection range spanning from 0 – 90 μM, with a LOD as low as 2.25 μM, also exhibits exceptional sensitivity (KD ∼ 0.8 × 104 M−1) and remarkable selectivity for Fe3+ ions, harnessing the intrinsic photoluminescent characteristics of VS2 QDs. In addition, a sophisticated portable smartphone platform, integrated with a radiometric fluorescence probe specifically tailored for in-situ detection of Fe3+ at the point of care, exhibits a LOD of approximately 5.05 μM, a value that resides below the prescribed safety threshold. Thus, the proposed probe stands to function as an exceptionally potent sensing apparatus for the precise quantification of Fe3+ in complex real-world samples. © 2024 Elsevier B.V.
Alkali metal ion codoped Eu3+ activated yttrium orthovanadate with tunable photoluminescence properties for LEDs and anti-counterfeiting applications
(Elsevier Ltd, 2025) Anuradha; Arpita Dwivedi; Satyam Upadhyay; Amit Kumar Srivastava; Monika Srivastava; Rajneesh Kumar; Sanjay Kumar Srivastava
The present experimental report articulates a comprehensive investigation on the synthesis, structural, and photoluminescence characteristics of M0.05,Eu0.05:Y0.90VO4 (M = Li+, Na+, K+) nanophosphors synthesised by auto-combustion approach, for optical display and anticounterfeiting technologies. Various characterization tools such as X-ray diffractometer (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Fourier transform infra-red (FTIR) Spectroscope, and Raman spectroscope have been employed to understand the morphology and crystal structure of M0.05,Eu0.05:Y0.90VO4 (M = Li+, Na+, K+) nanophosphor, which reveals the formation of a pure tetragonal structure and well crystalline phase. Moreover, the UV–Vis spectra, suggests that the as-synthesised material substantiated to possess an energy band gap of ∼3.6 eV conjecturing it as a wide-band material, and the refractive index (n) of the prepared samples has been deduced as ∼ 2.1. Among all alkali ions, Li+-codoped sample exhibits the most intense PL spectra. The enhancement in PL intensity has been observed due to the energy transfer of VO43−→Eu3+ and the codoping of lithium ions acts as a good charge compensator. For the optimized sample CIE coordinates has been found as (0.59, 0.39) and CCT value as 1712 K, which suggest it as a prospective candidate for the warm LEDs. The optimized sample has further been investigated for the visualization of Latent fingerprint on glass slide and as security ink. It displays efficient applicability as a well-defined ridge features up to level III. Henceforth, the as-synthesised Li0.05,Eu0.05:Y0.90VO4 nanophosphor may potentially be applied for multipurpose applications. © 2024 Elsevier Ltd and Techna Group S.r.l.
Allethrin-induced genotoxicity and oxidative stress in Swiss albino mice
(Elsevier B.V., 2012) Amit Kumar Srivastava; Pramod Kumar Srivastava; Abdulaziz A. Al-Khedhairy; Javed Musarrat; Yogeshwer Shukla
Allethrin (C19H26O3) is non-cyano-containing pyrethroid insecticide that is used extensively for controlling flies and mosquitoes. Apart from its neurotoxic effects in non-target species, allethrin is reported to be mutagenic in bacterial systems. In this study, we observed oxidative damage-mediated genotoxicity caused by allethrin in Swiss albino mice. The genotoxic potential of allethrin was evaluated using chromosome aberrations (CAs) and a micronuclei (MN) induction assay as genetic end-points. The oral intubation of allethrin (25 and 50mg/kg b.wt.) significantly induces CAs and MN in mouse bone marrow cells. The DNA-damaging potential of allethrin was estimated in mouse liver using the DNA alkaline unwinding assay (DAUA) and by measuring the levels of 8-hydroxy-2'-deoxy-guanosine (8-OH-dG). Furthermore, a dose-dependent increase in reactive oxygen species (ROS) generation and lipid peroxidation (LPO), with a concurrent decrease in superoxide dismutase (SOD) and catalase, confirm its pro-oxidant potential. The DNA-damaging potential of allethrin was found to be mediated through the modulation of p53, p21, GADD45α and MDM-2. These results confirm the genotoxic and the pro-oxidant potential of allethrin in Swiss albino mice. © 2012.
Comprehensive analysis of structural, morphological, surface chemistry, and optical traits of multifaceted SrTiO3 for enhanced photocatalytic and DSSC applications
(Elsevier Ltd, 2025) Satyam Upadhyay; Monika Srivastava; Pradyum Patel; Amit Kumar Srivastava; Dhananjay Kumar; Somnath C. Roy; Sanjay Kumar Srivastava
The present study underlines the facile synthesis of SrTiO3 nanoparticles through sol-gel approach and subsequently its dual applicability as photocatalyst for methylene blue degradation and photoanode in dye-sensitized solar cell fabrication. Structural and optical characterizations, including XRD with Rietveld refinement, SEM, TEM, XPS, Raman, UV–Vis, and PL spectroscopy, confirms a cubic perovskite phase with an optical bandgap of ∼3.24 eV. The ST NPs demonstrates enhanced photocatalytic activity under visible light, degrading ∼56.13 % of 10 ppm MB in 120 min. Kinetic studies under UV light further validated the degradation mechanism. As photoanodes in DSSCs, the ST NPs exhibit enhance photocurrent responses, especially when combined with natural pomegranate dye, suggesting their viability for renewable energy devices. These findings highlight the potential of strontium titanate nanoparticles for both photocatalytic applications and dye-sensitized solar cell fabrication, offering an eco-friendly and effective solution to address energy and environmental challenges. © 2025 Elsevier Ltd
Impact of Eu3 +/Y3+ doping on the structural and optical properties of SrTiO3 perovskite phosphor and multi-functional applications
(Elsevier Ltd, 2025) Satyam Upadhyay; Arpita Dwivedi; Prateek Kumar Yadav; Monika Srivastava; Amit Kumar Srivastava; Chandan Upadhyay; Sanjay Kumar Srivastava
A latent fingerprint (LFP) examination is essential for identifying fingerprints at crime sites, and personal data for legal operations requires economical, eco-friendly, and sensitive new materials. Here, a new composition of intense red-emitting Eu3+ and Y3+ co-doped SrTiO3 perovskites nanophosphor synthesized using a modified sol-gel-assisted combustion technique has been reported. To explore the structural and optical features of the nanophosphors the samples are characterized by various techniques. The powder XRD pattern reveals that the approximate crystallite size is 30 nm, which is consistent with TEM. It is found that with the mid- and near-ultraviolet light excitation, Eu3+ and Y3+ co-doped SrTiO3 nanophosphor displays a strong red emission at 618 nm for optimal concentrations (3 mol% Eu). The CIE (0.656, 0.344), color purity 95 %, CRI 98 %, and CCT values 2435 K, which is less than 5000 K reveals that the Eu3+ and Y3+ co-doped SrTiO3 phosphor was highly useful for the fabrication of warm LED and display device applications. Further, the optimized phosphor was tested (under UV light of 254 nm) for the visualization of LFP and security ink on various material surfaces. The results demonstrated that it provides an effective method for visualizing ridge patterns, offering a promising approach for applications in these areas. Based on the findings, Eu3+ and Y3+ co-doped SrTiO3 show potential for various optoelectronic applications, including WLEDs, LFP detection, security inks, and LEDs. © 2025 Elsevier B.V.
Mancozeb-induced genotoxicity and apoptosis in cultured human lymphocytes
(Elsevier Inc., 2012) Amit Kumar Srivastava; Wahid Ali; Richa Singh; Kulpreet Bhui; Shilpa Tyagi; Abdulaziz A. Al-Khedhairy; Pramod Kumar Srivastava; Javed Musarrat; Yogeshwer Shukla
Aims: Mancozeb is a dithiocarbamate fungicide known to be genotoxic and induces tumors in rodents at various sites. There is no report in the literature about its genotoxicity in humans. Here, we investigated the association between mancozeb exposure and induction of genotoxic and proapoptotic changes in cultured human lymphocytes (CHLs). Main methods: Lymphocytes were isolated from peripheral blood of healthy non-smoking donors. Induction of micronuclei and chromosomal aberrations was recorded both by conventional and flow cytometric methods. Annexin-V FITC was used for the differentiation of apoptotic and necrotic cells by flow cytometry. Key findings: Mancozeb exposure (0.5, 2 and 5 μg/ml) to CHLs leads to significant induction in the frequency of chromosomal aberrations (CAs) and micronuclei (MN), in a dose-dependent manner. Concomitantly, pro-oxidant potential of mancozeb was also recorded, by increase in the levels of reactive oxygen species (ROS) generation. Our results demonstrated that ROS plays a critical role in the initiation of mancozeb induced apoptosis in CHLs through two ways, primarily through mitochondria-mediated pathway including induction of ROS, decrease in mitochondrial membrane potential (ΔΨm), along with cytochrome c release from mitochondria, and activation of the caspase cascade. The other pathway includes increase in ROS, which resulted in activation of NF-κB, expression of FasL and triggered FasL-dependent pathway, which also involves caspase-8. Therefore, exposure to mancozeb can lead to induction of apoptosis in CHLs through both mechanisms. Significance: The results of study confirm that mancozeb exposure can induce genotoxicity and apoptosis in CHLs, thus pose a potential risk to exposed human population. © 2012 Elsevier Inc. All rights reserved.
Retraction notice to “Allethrin-induced genotoxicity and oxidative stress in Swiss albino mice” [MUTGEN 747 (1) (2012) 22–28](S1383571812000733)(10.1016/j.mrgentox.2012.03.003)
(Elsevier B.V., 2020) Amit Kumar Srivastava; Pramod Kumar Srivastava; Abdulaziz A. Al-Khedhairy; Javed Musarrat; Yogeshwer Shukla
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. In this article Figure 2 is described as depicting flow cytometry data of micronuclei induced by allethrin at different doses, but the figure contains duplications which affect the conclusions of the article. The authors have not been able to provide any justification for this image manipulation. As such this article represents a misuse 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. © 2019
Retraction notice to “Mancozeb-induced genotoxicity and apoptosis in cultured human lymphocytes” [Life Sci. 90/21-22 (2012) 815 - 824] (Life Sciences (2012) 90(21–22) (815–824), (S0024320512000021), (10.1016/j.lfs.2011.12.013))
(Elsevier Inc., 2022) Amit Kumar Srivastava; Wahid Ali; Richa Singh; Kulpreet Bhui; Shilpa Tyagi; Abdulaziz A. Al-Khedhairy; Pramod Kumar Srivastava; Javed Musarrat; Yogeshwer Shukla
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. Multiple figures in this article appear to be falsified/fabricated. Fig. 2 shows manipulated dot plots for two different treatment groups (2 μl/ml and 5 μl/ml). Fig. 6 (caspase 9 blot) is very similar to fig. 5 (total ERK1/2) of a previous paper from this group published in Cancer Letters, 282, (2009) 67–176, https://doi.org/10.1016/j.canlet.2009.03.003. In Fig. 4, Lanes 4 and 5 are identical for most of their lengths, with only cosmetic changes along the edges of the upper half. Fig. 6 contains similar portions of Fig. 2(a) of a paper published by the same group in Food and Chemical Toxicology, 49, (2011) 1511–1520, https://doi.org/10.1016/j.fct.2011.03.040 The authors have not been able to provide any justification for this image manipulation. © 2022 Elsevier Inc.
Solution-Processed ZnO/V2O5Heterojunction Thin Films for UV Photodetectors
(American Chemical Society, 2025) Prateek Kumar Yadav; Sandeep Dahiya; Bhola Nath Pal; Amit Kumar Srivastava; Amritanshu Pandey; Sanjay Kumar Srivastava
This study delineates the fabrication and evaluation of a high-performing ultraviolet (UV) photodetector (PD) consisting of a ZnO/V2O5nanoparticle (NP) bilayer thin film deposited on a Si/SiO2substrate through spin coating. Various analytical techniques, such as X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy, have been employed to investigate the structural features and surface morphology of the as-prepared samples. The V2O5NPs were prepared through a facile one-pot solvothermal process, while ZnO NPs were obtained through a rapid sol–gel method. V2O5NPs demonstrate extended absorption with significant absorption in the range of 240–450 nm and exhibit a relatively smaller band gap. The optoelectronic features of as-deposited thin films have primarily been studied through I–V characteristics under dark and UV light conditions with the same external bias of 2 V, and the photocurrent has been found to be 9.13 × 10–5A/cm2, which is ∼2.77 × 103times higher than the dark current. The obtained photocurrent-to-dark current ratio for the ZnO/V2O5device is nearly ∼1.37 × 102times higher than that of the ZnO-only device. Moreover, this bilayer UV PD exhibits a detectivity (D) of ∼3.1 × 1012Jones, a spectral responsivity (R) of ∼4 A/W, and an external quantum efficiency (EQE) of ∼16% under an external potential of 10 V. Furthermore, the findings are analyzed, and an explanation of the detailed photodetection mechanism is outlined in this paper. © 2025 American Chemical Society