In this study, we report gram flour‐derived carbon quantum dots (GFCQDs) synthesized via a green microwave‐assisted approach that acts as dual sensor for the sensing of both fluoroquinolones and tetracyclines, showing fluorescence enhancement with a slight bathochromic shift in emission wavelength and fluorescence quenching, respectively. Mechanistic studies revealed that the detection of tetracycline relies on the inner filter effect, while ciprofloxacin detection involves hydrogen bond‐based interactions. GFCQDs can selectively detect tetracycline by a fluorescence color change from blue to green in the presence of calcium and can also detect antibiotics within a mixed antibiotic pool. The practical applicability was evaluated in real samples (milk, tap water, and food) and pharmaceutical formulations with recovery rates ranging from 97% to 99%. GFCQDs can be transformed into portable cellulose paper strips as a handy tool for on‐site and off‐site detection of antibiotics. Furthermore, GFCQDs successfully sensed tetracycline through a blue fluorescence “turn‐off” response in the bacterial strain Bacillus subtilis .
The development of sustainable and biocompatible fluorescent nanomaterials is essential for advancing next‐generation bioimaging and sensing technologies. This work reports an economical green synthesis of carboxyl‐functionalized, N,K codoped carbon quantum dots (cq‐hCQDs) derived from Cissus quadrangularis via a facile hydrothermal approach. The resulting cq‐hCQDs possess a quasispherical morphology (~3.23 nm), hybrid sp 2 ‐sp 3 carbon architecture, and abundant ─COOH surface functional groups, enabling excellent hydrophilicity, aqueous stability, and chemical reactivity, as evidenced from HRTEM, XPS, NMR, FTIR, and zeta potential. The cq‐hCQDs exhibit enhanced visible‐light absorption with a narrowed bandgap (~2.85 eV) and strong, tunable fluorescence dominated by π –π * transitions, alongside contributions from surface and defect states introduced by heteroatom doping. A plausible mechanism is proposed in which the synergistic electronic modulation may contribute to enhanced emission intensity through multiple radiative recombination pathways. Notably, the synthesized cq‐hCQDs exhibited potential as fluorescent bioimaging probes, providing high‐contrast visualization of cellular structures in Funaria hygrometrica moss and Ficus religiosa plant tissues. Furthermore, phytotoxicity analysis validates marginal biological impact, with >75% cell survivability.
Residual accumulation of conventional fertilizers in soil imposes severe environmental stress and amplifies long‐term economic burdens. The emergence of nanotechnology offers a paradigm shift with carbon quantum dots (CQDs) emerging as a particularly promising candidate. CQDs are quasi‐spherical, fluorescent carbon nanoparticles below 10 nm in size, renowned for their high‐water solubility, low toxicity, biocompatibility, and tunable surface chemistry. This review focuses on the recent and emerging advances of mineral‐doped carbon quantum dots (M‐CQDs) and their fundamental chemistry of synthesis and doping mechanisms. The complex interactions of M‐CQDs in plant systems are thoroughly outlined as follows (i) a targeted nutrient delivery system, (ii) a potent photosensitizer for enhanced photosynthetic efficiency, (iii) a robust elicitor of plant defense mechanisms, and (iv) a modulator of soil microbial communities. The current research landscape and future directions are outlined to unlock the full potential of M‐CQDs as smart, sustainable next‐generation quantum fertilizers.
Anisotropic nanostructures with controllable and well‐defined shapes, compositions, and surface morphologies have been augmented as important building blocks toward the design of functional materials. Recent advances in the “tips and tricks” have enabled the synthesis of nanoscale materials through newer routes with various morphologies and facet orientations. The control of shape has shown promise for physical attributes emanating from the anisotropy of the nanostructures. In this Review, we aim to elucidate the mayhems associated with the growth of anisotropic gold nanostructures in the colloidal dispersion. We have surveyed some specific examples to illustrate the diverse methodologies that can be adopted for the synthesis of shape‐selective nanostructures. It has been revealed that the choice of the chemical environment governs both the surface energies and crystallinity of the anisotropic nanostructures; the cumulative permutations of crystallinity and surface facets can be intermixed to produce newer morphologies of the nanocrystals. We have elucidated the kinetic and thermodynamic factors to imbue shape‐selective nanostructures from both theoretical and experimental perspectives. Finally, we have concluded with some thoughts on the present state‐of‐the‐art advances in this research arena, the future potential of such concepts, and the plausible limitations to be overcome associated with shape‐defined nanostructures.
Metal–organic frameworks (MOFs) are significant porous materials for various environmental applications. In this work, we synthesized a well‐known MOF Zeolitic Imidazolate Framework‐8 (ZIF‐8). We then modified ZIF‐8 with 0.6 mmol of Palmitic acid (PA) to obtain superhydrophobic 0.6PA@ZIF‐8 (contact angle of 152.15° ± 1.43°). The 0.6PA@ZIF‐8 was then used to remove Fipronil (FP), an insecticide. The ZIF‐8 and 0.6PA@ZIF‐8 were then characterized using data from powder X‐ray diffraction (P‐XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR). Thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), X‐ray photoelectron spectroscopy (XPS), and Raman spectroscopy. P‐XRD and Raman spectroscopy data after FP adsorption onto 0.6PA@ZIF‐8 indicated hydrophobic and weak interactions between FP and 0.6PA@ZIF‐8. The pseudo‐second‐order kinetic model described FP uptake by 0.6PA@ZIF‐8. Adsorption isotherm models were constructed, and Sips/Hill Isotherm model with an R 2 value of 0.9919 was found to be the best fit. The mechanism of FP adsorption on 0.6PA@ZIF‐8 was primarily governed by hydrophobic interaction, due to bound PA tails on the external surface of ZIF‐8. The 0.6PA@ZIF‐8 was then utilized to remove the FP from the real sample for its practical application. Finally, consecutive adsorption–desorption recycling experiments, accompanied by post‐cycling characterizations, were evaluated to confirm the MOF regeneration efficiency.
