6. Arka Sanyal, Pokala Gopi Krishna, Vinith Johnson & Uday Kumar S "Mechanistic insights into photoactive interfaces of mesoporous Ag–ZnO nanohybrids for mitigation of recalcitrant organic pollutants" Applied Surface Science Dec 2025.
Abstract: This work reports a facile, one-pot microwave-assisted strategy for the synthesis of mesoporous Ag–ZnO nanohybrids using diethylene glycol as a mild reducing medium. The approach enables uniform deposition of Ag on ZnO, forming highly crystalline, quasi-spherical nanostructures (≈25–45 nm) with a specific surface area of 34.39 m2/g−1 and dominant mesoporosity (∼3.827 nm). Structural and surface analyses (XRD, FTIR, FESEM, S-TEM, and XPS) confirmed the coexistence of FCC Ag and wurtzite ZnO phases, and oxygen-deficient surface sites. UV–Vis spectroscopy revealed a redshifted absorption edge (∼390 nm) and a reduced band gap (3.18 eV), while photoluminescence quenching indicated suppressed charge recombination at the Ag-ZnO interface. The nanohybrids exhibited outstanding visible-light photocatalytic activity, achieving 97.15 % degradation of MO and 93.17 % removal of SDS within 150 min, alongside rapid catalytic reduction of 4-nitrophenol to 4-aminophenol. Radical trapping experiments identified •O2− and •OH as the dominant reactive species. Furthermore, the catalyst retained high performance over multiple cycles, demonstrating robust stability and reusability. Importantly, TOC reduction and improved seed germination in treated effluents confirmed effective mineralization and reduced phytotoxicity. These findings provide mechanistic insights into Ag–ZnO interfacial charge dynamics and highlight the system’s potential for sustainable water remediation
5. Vinith Johnson., Sunil V & Uday Kumar S., “ A rapid route to perovskites: barium titanate nanoparticles via microwave-assisted solvothermal synthesis" Nanoscale. Nov 2025
Abstract: Barium titanate (BaTiO3) is a Hypothesized the work and performed all necessary experimentsperovskite material with remarkable dielectric, ferroelectric, and piezoelectric properties, making it valuable in biomedical and functional devices. Its performance depends on the crystal structure, phase purity, and particle size. Conventional synthesis methods are energy-intensive and less scalable. Microwave-assisted solvothermal synthesis provides a more efficient and scalable alternative, enabling better control over particle characteristics. In this work, BaTiO3 nanoparticles (BTNPs) were prepared using the microwave-assisted solvothermal approach to examine how the reaction time affects their structural and functional behaviour. Detailed characterization revealed that the sample synthesized within 30 minutes achieved the highest crystallinity and the lowest defect density. This sample also exhibited fewer surface-bound organic residues, mainly oxygen-bound metal precursors, compared to other samples. Morphological analysis revealed that the 30 minute synthesis yielded smaller, well-crystallized particles, whereas extending the reaction time led to agglomeration. These observations were further supported by surface potential measurements, which indicated improved colloidal stability. Overall, 30 minutes was identified as the optimal synthesis time, producing BTNPs with superior crystallinity, phase purity, and functional properties. This study underscores the microwave-assisted solvothermal approach as a rapid, energy-efficient, and scalable method to produce high-quality BTNPs for applications in the dielectric, optoelectronic, and biomedical fields.
4. Sunil V., Anurag Sharma., Vinith Johnson., Uday Kumar S., “ Turn-Off Fluorometric Detection of Co2+ by Polyethylenimine-Passivated Carbon Nanoprobes: Mechanistic Insights through ITC" ACS Applied Bio materials. Aug 2025.
Abstract: The development of sensitive and selective probes for cobalt ion (Co2+) detection is critical, given the increasing environmental burden of heavy metal contamination from industrial discharge and its consequences on lifeforms. To this end, we present polyethylenimine-passivated carbon dots (PEI-MCDs), synthesized via a rapid microwave-assisted pyrolysis of Moringa oleifera leaves, as efficient fluorescent nanoprobes for Co2+ detection. Comprehensive spectroscopic and microscopic analyses confirmed that the PEI-MCDs are water-soluble and exhibit excitation-dependent emission. The nanoprobes exhibited a wide linear detection range (20–180 μM) and a low detection limit of 1.1 μM for Co2+ detection, with high accuracy in real water samples. Further investigation of the selective affinity of PEI-MCDs to Co2+ ions with isothermal titration calorimetry (ITC) revealed van der Waals force-driven strong and specific exothermic interactions at the interface. Complementary time-resolved fluorescence studies indicated that Förster resonance energy transfer (FRET) contributes to the observed fluorescence quenching upon Co2+ binding, offering further insight into the energy transfer dynamics at the nanoprobe interface. Together, these findings offer a comprehensive mechanistic understanding of the Co2+-nanoprobe interaction, establishing PEI-MCDs as a promising sustainable platform for reliable, real-time fluorometric detection of cobalt ions in complex water bodies.
3. Sunil V., Damini V., Surya S., Anki Reddy K., Gopinath P., Uday Kumar S., “In situ Ag seeded lamellar Ti3C2 nanosheets: An Electroactive interface for Non-Invasive Diagnosis of Oral Carcinoma a via Salivary TNF-α Sensing.” ACS Applied Bio materials. 2025 Jan.
Abstract: In the fast-paced quest for early cancer detection, non-invasive screening techniques have emerged as game-changers, offering simple and accessible avenues for precession diagnostics. In line with this, our study highlights the potential of silver nanoparticle-decorated titanium carbide MXene nanosheets (Ti3C2_AgNPs) as an electroactive interface for noninvasive diagnosis of oral carcinoma based on the prevalence of salivary biomarker, Tumour necrosis factor-α (TNF-α). An in-situ reduction was utilized to synthesize Ti3C2_AgNPs nanohybrid wherein Ti3C2 acts as the reducing agent and the resulting nanohybrid was subjected to various characterization techniques to examine the optical, structural and morphological attributes. The results revealed that spherical AgNPs formed on the surface of Ti3C2 MXene nanosheets by virtue of the low valent Ti species present in Ti3C2, which facilitated the reduction of AgNO3 to AgNPs. Further, the electrochemical characterization of nanohybrid modified screen printed electrode (Ti3C2_AgNPs/SPE) indicated enhanced heterogeneous electron transfer kinetics. With these encouraging results, Ti3C2_AgNPs nanohybrid was employed as an immobilization matrix for TNF-α antibodies and applied for electrochemical sensing. The analytical studies of fabricated immunosensor conducted by differential pulse voltammetry (DPV) exhibited a broader linear range (1 pg mL-1 to 180 pg mL-1), low limit of detection (0.97 pg mL-1 ), high sensitivity (1.214 μA mL pg-1 cm-2) and specificity even in artificial saliva indicating itsreliability for OSCC diagnosis. Therefore, the Ti3C2_AgNPs nanohybrid seems a promising candidate for effective sensing of TNF-α and could also be explored for other biomarkers.
2. Sunil V., Vinith J., Archana M., Anki Reddy K., Uday Kumar S., “Circulating Extracellular Vesicles as Promising Biomarkers for Precession Diagnostics: A Perspective on Lung Cancer” ACS Biomaterials Science & Engineering. 2024 Dec.
Abstract: Extracellular vesicles (EVs) have emerged as promising biomarkers in liquid biopsy, owing to their ubiquitous presence in bodily fluids and their ability to carry disease-related cargo. Recognizing their significance in disease diagnosis and treatment, substantial efforts have been dedicated to developing efficient methods for EV isolation, detection, and analysis. EVs, heterogeneous membrane-encapsulated vesicles secreted by all cells, contain bioactive substances capable of modulating recipient cell biology upon internalization, including proteins, lipids, DNA, and various RNAs. Their prevalence across bodily fluids has positioned them as pivotal mediators in physiological and pathological processes, notably in cancer, where they hold potential as straightforward tumor biomarkers. This review offers a comprehensive examination of advanced nanotechnology-based techniques for detecting lung cancer through EV analysis. It begins by providing a brief overview of exosomes and their role in lung cancer progression. Furthermore, this review explores the evolving landscape of EV isolation and cargo analysis, highlighting the importance of characterizing specific biomolecular signatures within EVs for improved diagnostic accuracy in lung cancer patients. Innovative strategies for enhancing the sensitivity and specificity of EV isolation and detection, including the integration of microfluidic platforms and multiplexed biosensing technologies are summarized. The discussion then extends to key challenges associated with EV-based liquid biopsies, such as the standardization of isolation and detection protocols and the establishment of robust analytical platforms for clinical translation. This review highlights the transformative impact of EV-based liquid biopsy in lung cancer diagnosis, heralding a new era of personalized medicine and improved patient care.
1. Vinith J., Sunil V., Uday Kumar S., Manoj K., “Surface-Engineered Extracellular Vesicles in Cancer Immunotherapy” Cancers (Basel). 2023 May; 15(10): 2838.
Abstract: Extracellular vesicles are small membranous particles secreted by cells. Extracellular vesicles facilitate the transportation of biomolecules, such as protein, RNA, and DNA fragments, to communicate with neighboring and distant cells. Cancer cells use extracellular vesicles to hijack the immune system and induce cancer-promoting signals. Modifying extracellular vesicles using surface engineering tools allows the addition of biomolecules for targeted delivery, thus modulating the hijacked tumor immune microenvironment to improve therapeutic efficacy. This review article discusses extracellular vesicle modification strategies explicitly focusing on the approaches used for surface engineering. We revisit the work carried out on the surface-engineered extracellular vesicle and its application in immunomodulating tumor microenvironments for cancer immunotherapy.