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.