Browsing by Author "Sivaselvam, S"

Now showing 1 - 3 of 3
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    Biocompatible InP/ZnSeS quantum dots/MXene composite as highly sensitive electrochemical sensors for carbendazim pesticide
    (Applied Surface Science, 2024-11) Sharma, TSK; Jana, J; Sivaselvam, S; Babu, B; Jayasree, RS; Mishra, Y; Hur, SH; Choi, WM
    In this study, we prepared InP/ZnSeS QDs anchored on MXene hybrid composite (IZQ-MX) for precise electrochemical sensing of carbendazim (CBZ) pesticide in food and environmental samples. The resulting electrochemical detection of CBZ exhibited a wide linear range of 0.019–527.6 μM, with a low detection limit of 14.59 nM and high sensitivity of 9.9026 µA·µM−1·cm−2. The environmental safety of IZQ-MX composite was further studied using in-vitro and in-vivo model. In L929 cells, exposure to IZQ-MX (0–100 nM) did not induce any significant change in cell viability, intracellular ROS generation and morphological changes. The exposure to IZQ-MX (0–200 nM) in C. elegans has also no significant change in primary and secondary endpoints of nematodes, neuronal development, DAF-16/FOXO and SKN-1/Nrf-2 transcription factors regulating the antioxidant genes. Environmental safety assessment of the IZQ-MX composite was performed using in-vitro and in-vivo models which demonstrated excellent biocompatibility. This work demonstrated the potential of IZQ-MX as significant electrocatalyst in sensitive and selective detection of CBZ for practical applications.
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    Nanoarchitectonics of fluorescent gold nanoclusters: A platform for image guided photodynamic therapy of hypoxic tumor
    (Applied Materials Today, 2024-06) Resmi, AN; Sivaselvam, S; Papasouli, E; Kunnumpurathu, J; Praveen, CS; Koukaras, EN; Rerat, M; Karamanis, P; Jayasree, RS
    Metal nanoclusters are atomically precise materials comprising metal core of few atoms exhibiting unique photoluminescence properties, unlike their bigger counterparts. Some metal nanocluster with ligand-to-metal charge transfer, long-lived excited state and excited triplet state contribute to inherent photosensitizing (PS) property. However, the therapeutic efficacy of PDT is hindered by the insufficient oxygen supply (O2) in tumor microenvironment. In the present work, cysteine-capped gold nanocluster (AuC) are studied for their unique molecular architecture for PS efficiency. The co-existence of monodispersed and self-assembled structures contribute to the photoluminescence from the quantum confinement of electronic states and aggregation-induced emission (AIE) based PS property, respectively. In-silico model was performed to study the interaction of cysteine to gold cluster, its ground and excited-state properties and the charge transfer mechanism. The AuC as PS generates cytotoxic radicals in both Type I and Type II photodynamic pathways and the dominant radical species involved were elucidated by EPR spectroscopy. In vitro analysis in HeLa cells showed excellent biocompatibility and bioimaging properties. The intracellular ROS production and Live/Dead assay confirmed the generation of ROS in HeLa cells upon laser irradiation. The image-guided photodynamic property with synergistic Type I and Type II PDT reactions of AuC promises its potential application in cancer therapy in both hypoxic and normoxic conditions
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    Nitrogen doped carbon quantum dots for bioimaging and detection of norfloxacin residues in food samples
    (Journal of Materials Chemistry B, 2024-07) Sivaselvam, S; Anjana, RS; Dhujana, NS; Victor, M; Jayasree, RS
    Incomplete metabolism and non-biodegradable nature of norfloxacin (NORx) lead to its persistent residues in the environment and food, potentially fostering the emergence of antibiotic resistance and posing a significant threat to public health. Hence, we developed a norfloxacin sensor employing hydrothermally synthesized N-doped carbon dots (N-Ch-CQDs) from chitosan and PEI demonstrated high sensitivity and specificity towards the antibiotic detection. The quantum yield of excitation-dependent emission of N-Ch-CQDs was effectively tuned from 4.6 to 21.5% by varying the concentration of PEI (5–15%). With the enhanced fluorescence in the presence of norfloxacin, N-Ch-CQDs exhibited a linear detection range of 20–1400 nM with a limit of detection (LoD) of 9.3 nM. The high biocompatibility of N-Ch-CQDs was confirmed in the in vitro and in vivo model and showed the environment-friendly nature of the sensor. Detailed study elucidated the formation of strong hydrogen bonds between N-Ch-CQDs and NORx, leading to fluorescence enhancement. The developed sensor's capability to detect NORx was evaluated in water and milk samples. The recovery rate ranged from 98.5% to 103.5%, demonstrating the sensor's practical applicability. Further, the bioimaging potential of N-Ch-CQDs was demonstrated in both the in vitro (L929 cells) and in vivo model (C. elegans). The synergistic influence of the defecation pattern and functioning of intestinal barrier mitigates the translocation of N-Ch-CQDs into the reproductive organ of nematodes. This study revealed the bioimaging and fluorescent sensing ability of N-Ch-CQDs, which holds significant promise for extensive application in the biomedical field.