Kundu Aayushi, Maity Banibrata, Basu Soumen
School of Chemistry and Biochemistry, Senior Research Fellow-TIET-Virginia Tech Center of Excellence in Emerging Materials, Thapar Institute of Engineering and Technology, Patiala 147004, India.
School of Chemistry and Biochemistry, Affiliate Faculty-TIET-Virginia Tech Center of Excellence in Emerging Materials, Thapar Institute of Engineering and Technology, Patiala 147004, India.
ACS Omega. 2023 Jun 6;8(24):22178-22189. doi: 10.1021/acsomega.3c02474. eCollection 2023 Jun 20.
Green-emissive carbon quantum dots (CQDs) with exclusive chemosensing aspects were synthesized from orange pomace as a biomass-based precursor a facile microwave method without using any chemicals. The synthesis of highly fluorescent CQDs with inherent nitrogen was confirmed through X-ray diffraction, X-ray photoelectron, Fourier transform infrared, Raman, and transmission electron microscopic techniques. The average size of the synthesized CQDs was found to be 7.5 nm. These fabricated CQDs displayed excellent photostability, water solubility, and outstanding fluorescent quantum yield, , 54.26%. The synthesized CQDs showed promising results for the detection of Cr ions and 4-nitrophenol (4-NP). The sensitivity of CQDs toward Cr and 4-NP was found up to the nanomolar range with the limit of detection values of 59.6 and 14 nM, respectively. Several analytical performances were thoroughly studied for high precision of dual analytes of the proposed nanosensor. Various photophysical parameters of CQDs (quenching efficiency, binding constant, ) were analyzed in the presence of dual analytes to gain more insights into the sensing mechanism. The synthesized CQDs exhibited fluorescence quenching toward incrementing the quencher concentration, which was rationalized by the inner filter effect through time-correlated single-photon counting measurements. The CQDs fabricated in the current work exhibited a lower detection limit and a wide linear range through the simple, eco-friendly, and rapid detection of Cr and 4-NP ions. To evaluate the feasibility of the detection approach, real sample analysis was conducted, demonstrating satisfactory recovery rates and relative standard deviations toward the developed probes. This research paves the way for developing CQDs with superior characteristics utilizing orange pomace (biowaste precursor).
以橙皮渣为生物质基前驱体，采用简便的微波法，不使用任何化学试剂，合成了具有独特化学传感特性的绿色发光碳量子点（CQDs）。通过X射线衍射、X射线光电子能谱、傅里叶变换红外光谱、拉曼光谱和透射电子显微镜技术，证实了具有固有氮的高荧光CQDs的合成。合成的CQDs平均尺寸为7.5nm。这些制备的CQDs表现出优异的光稳定性、水溶性和出色的荧光量子产率，为54.26%。合成的CQDs对Cr离子和4-硝基苯酚（4-NP）的检测显示出有前景的结果。发现CQDs对Cr和4-NP的灵敏度高达纳摩尔范围，检测限分别为59.6和14 nM。为了提高所提出的纳米传感器对两种分析物的检测精度，对其几种分析性能进行了深入研究。在两种分析物存在的情况下，分析了CQDs的各种光物理参数（猝灭效率、结合常数等），以更深入地了解传感机制。合成的CQDs表现出随着猝灭剂浓度增加而发生荧光猝灭，通过时间相关单光子计数测量，这可以通过内滤效应来解释。当前工作中制备的CQDs通过简单、环保且快速地检测Cr和4-NP离子，表现出较低的检测限和较宽的线性范围。为了评估检测方法的可行性，进行了实际样品分析，结果表明对所开发的探针具有令人满意的回收率和相对标准偏差。本研究为利用橙皮渣（生物废弃物前驱体）开发具有优异特性的CQDs铺平了道路。
