Rani Yogita, Km Mamata Patel, Tripathi Prabhat
Department of Chemistry, Indian Institute of Technology (BHU), Varanasi 221005, Uttar Pradesh, India.
ACS Appl Mater Interfaces. 2024 Dec 18;16(50):68936-68949. doi: 10.1021/acsami.4c15636. Epub 2024 Dec 5.
Creating an analytical probe to track extremely mutagenic picric acid (PA) is essential for human health and the environment. Here, we developed a straightforward and quick fluorescence analytical method utilizing 3-aminopropyltrimethoxysilane (3-APTMS)-functionalized curcumin carbon quantum dots (CQDs) for the fast and selective detection of PA. Solvothermal carbonization and functionalization of curcumin with 3-APTMS were used to create multifunctional CQDs, which were then characterized using UV-vis spectroscopy, Fourier transform infrared (FTIR), X-ray diffraction (XRD), ζ-potential, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Our CQDs, as synthesized with an average diameter of 3.4 nm, exhibited excitation-dependent emission behavior, demonstrating 63.85% yield, 1.59% quantum yield, and fluorescence lifetime decay broader than a single exponential. The addition of picric acid significantly reduced the fluorescence (FL) emission intensity of CQDs and caused a noticeable color shift in visible as well as UV light. Throughout the 0.1-2.5 μM range, the calibration curve of the suggested assay demonstrated favorable linearity between quenched FL emission intensity and PA concentration, with the lowest detection limit of 88.96 nM. The CQD shows antioxidant activity at low concentrations (<0.07 mg/mL), measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay (colorimetry and electrochemically). Further, we encapsulated our CQDs in the liposome to make it biocompatible for cell imaging for future study. The results indicate the efficacy of CQDs as a nanoprobe for the selective detection of PA, retaining a few of the primary properties of natural curcumin-like antioxidant activity while having significantly higher bioavailability and water solubility; they can be used as a modifier in semiconductors for photocatalytic application and can also be a promising fluorescence probe in cell imaging.
创建一种用于追踪极具诱变作用的苦味酸（PA）的分析探针，对人类健康和环境至关重要。在此，我们开发了一种简单快速的荧光分析方法，利用3-氨丙基三甲氧基硅烷（3-APTMS）功能化的姜黄素碳量子点（CQDs）快速、选择性地检测PA。采用姜黄素与3-APTMS的溶剂热碳化和功能化反应制备多功能CQDs，然后通过紫外可见光谱、傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、ζ电位、透射电子显微镜（TEM）和X射线光电子能谱（XPS）对其进行表征。我们合成的CQDs平均直径为3.4 nm，表现出激发依赖的发射行为，产率为63.85%，量子产率为1.59%，荧光寿命衰减比单指数衰减更宽。苦味酸的加入显著降低了CQDs的荧光（FL）发射强度，并在可见光和紫外光下引起明显的颜色变化。在0.1 - 2.5 μM范围内，所建议检测方法的校准曲线表明猝灭的FL发射强度与PA浓度之间具有良好的线性关系，最低检测限为88.96 nM。通过2,2-二苯基-1-苦基肼（DPPH）测定法（比色法和电化学法）测得，CQDs在低浓度（<0.07 mg/mL）时具有抗氧化活性。此外，我们将CQDs包裹在脂质体中，使其具有生物相容性，以便用于未来的细胞成像研究。结果表明，CQDs作为一种纳米探针用于选择性检测PA是有效的，它保留了天然姜黄素的一些主要特性，如抗氧化活性，同时具有显著更高的生物利用度和水溶性；它们可作为半导体中的改性剂用于光催化应用，也有望成为细胞成像中的荧光探针。
