Browsing by Author "Vatti, A.K."

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    Fluorene-vanillin hybrid: A multifunctional fluorophore for latent fingerprint detection and sustainable offset security ink development
    (Elsevier B.V., 2025) K Jain, R.; P.j, A.; Dhanya, D.; Bhagavath, P.; Vatti, A.K.; Mahadeva Prasad, M.P.; K, U.B.; Alex, A.
    Fluorophores play a pivotal role in forensic science and anticounterfeit applications due to their unique and distinct emission features, which enable visualization and authentication. In the pursuit for advanced fluorescent pigments, ortho vanillin-fluorene Schiff base (OAF) with bright orange fluorescence was synthesized using a cost-effective, simple, and one-step method. This fluorophore was highly effective in developing latent fingerprints (LFPs), enabling visualization of level 1–3 features on nonporous glass and semi-porous leather under 365 nm UV light. The interaction between glycine in the fingerprint residue on glass substrate and OAF was analyzed through computational studies and further validated using ATR-FTIR analysis. The FESEM images of the latent prints revealed detailed surface morphology and particle distribution on the ridges of the fingermarks. Further, fluorescent images of LFPs were successfully developed on sticky paint, moist glass, multicolored compact disc, and uneven leaf surface, demonstrating the material's versatility on challenging substrates. Moreover, the powder dusting of composite powder of OAF and JUP-AS120, a commercially available pigment enabled enhanced LFP visualization on glass under both 365 and 980 nm light sources for better contrast and minimal background fluorescence, while minimising degradation of fingerprint residues over time. In addition, an OAF spray was formulated using nitrocellulose resin, ethyl acetate and carbitol for broader forensic application, which facilitated LFP visualization down to fine minutiae details on porous, semi-porous and non-porous substrates. Furthermore, to address the growing rates of counterfeited products/banknotes/security documents, an ecofriendly composite security ink was formulated using OAF and JUP-AS120 to obtain offset prints with excellent resistance to photobleaching and scuffing on paper substrate. The ink film exhibited multilevel authentication features: orange fluorescence under a 365 nm light source, and green and red emissions without and with a 610 nm band pass filter, respectively under 980 nm laser source, enhancing security and making forgery more challenging. Additionally, biocompatible OAF can be incorporated in ink pads to offer a dual layer of validation for fingerprints on security documents: optical authentication by leveraging the ink's fluorescence properties and biometric recognition through fingerprint patterns. © 2025 The Author(s)
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    Pyrene-based chalcones as functional materials for organic electronics application
    (Elsevier Ltd, 2023) Kagatikar, S.; Dhanya, D.; Kekuda, D.; Satyanarayana, M.N.; Kulkarni, S.D.; Sudhakar, Y.N.; Vatti, A.K.; Sadhanala, A.
    Though new generation organic electronic devices have evolved from mere scientific perceptions to real-life marketed applications, considerably less research attention has been focused on n-type or electron transporting small molecule semiconductors. The present study is focused on the exploration of structural, thermal, electrochemical, electrical, and optical properties of two pyrene-based chalcones: PC1 and PC2, synthesized through Claisen Schmidt condensation reaction. The chalcones displayed good thermal stability and wide bandgap n-type semiconducting behaviour with high charge carrier concentration and dielectric constant. The experimental evidences including fluorescence measurements, nanoaggregate size, and morphology analysis, supported by DFT calculations and molecular dynamic simulations advocated the intramolecular charge transfer and aggregation-induced enhanced emission features of the molecules. Successful fabrication of a diode in combination with the current-voltage characteristics established the candidature of PC1 and PC2 for electro-optical devices. The dielectric studies were performed to measure dielectric constant and AC conductivity at different frequency ranges. The cyclic voltammetry and AC impedance response of PC2 differed from PC1 due to the inclusion of a fluorine atom in the molecular scaffold. Further, the functional implication of PC2 as an electrode material was explored by constructing a supercapacitor, which offered a specific capacitance of 220 Fg-1 at a scan rate of 10 mV s−1. Moreover, these chalcone-based organic semiconductors displayed high thermal and charge carrier concentration as well as compatibility with other layers in an OLED device. Hence PC1/PC2 can be further investigated as dopants along with other emissive layers as host materials in OLEDs. © 2022 Elsevier B.V.