scholarly journals Construction of Photoelectrochemical DNA Biosensors Based on TiO2@Carbon Dots@Black Phosphorous Quantum Dots

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1523
Author(s):  
Kai Song ◽  
Jianwei Lin ◽  
Yafeng Zhuang ◽  
Zhizhong Han ◽  
Jinghua Chen

In this work, carbon dots (CDs) and black phosphorus quantum dots (BPQDs) were used to decorate titanium dioxide to enhance the photoelectrochemical (PEC) properties of the nanocomposites (TiO2@CDs@BPQDs), and the modified nanocomposites were used to sensitively detect DNA. We used the hydrothermal method and citric acid as a raw material to prepare CDs with good dispersion and strong fluorescence properties. BPQDs with a uniform particle size were prepared from black phosphorus crystals. The nanocomposites were characterized by fluorescence spectroscopy, UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The preparation method of the working electrode was explored, the detection conditions were optimized, and the sensitive detection of target DNA was achieved. The results demonstrate that CDs and BPQDs with good optical properties were successfully prepared, and they were successfully combined with TiO2 to improve the PEC performance of TiO2@CDs@BPQDs. The TiO2-based PEC DNA detection method was constructed with a detection limit of 8.39 nM. The constructed detection method has many advantages, including good sensitivity, a wide detection range, and good specificity. This work provides a promising PEC strategy for the detection of other biomolecules.

ACS Nano ◽  
2018 ◽  
Vol 12 (12) ◽  
pp. 12401-12415 ◽  
Author(s):  
Leung Chan ◽  
Pan Gao ◽  
Wenhua Zhou ◽  
Chaoming Mei ◽  
Yanyu Huang ◽  
...  

Author(s):  
Zhou J ◽  
◽  
Dong Y ◽  
Ma Y ◽  
Zhang T ◽  
...  

Graphene Quantum Dots (GQDs) have been prepared by oxidationhydrothermal reaction, using ball-milling graphite as the starting materials. The prepared GQDs are endowed with excellent luminescence properties, with the optimum emission of 320nm. Blue photoluminescent emitted from the GQDs under ultraviolet light. The GQDs are ~3nm in width and 0.5~2 nm in thickness, revealed by high-resolution transmission electron microscopy and atomic force microscopy. In addition, Fourier transform infrared spectrum evidences the existence of carbonyl and hydroxyl groups, meaning GQDs can be dispersed in water easily and used in cellar imaging, and blue area inside L929 cells were clearly observed under the fluorescence microscope. Both low price of raw material and simple prepared method contribute to the high quality GQDs widespread application in future.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Shibo Xu ◽  
Linna Chang ◽  
Yanan Hu ◽  
Xingjun Zhao ◽  
Shuocheng Huang ◽  
...  

Abstract Background Healing of MRSA (methicillin-resistant Staphylococcus aureus) infected deep burn wounds (MIDBW) in diabetic patients remains an obstacle but is a cutting-edge research problem in clinical science. Surgical debridement and continuous antibiotic use remain the primary clinical treatment for MIDBW. However, suboptimal pharmacokinetics and high doses of antibiotics often cause serious side effects such as fatal complications of drug-resistant bacterial infections. MRSA, which causes wound infection, is currently a bacterium of concern in diabetic wound healing. In more severe cases, it can even lead to amputation of the patient's limb. The development of bioactive nanomaterials that can promote infected wound healing is significant. Results The present work proposed a strategy of using EGCG (Epigallocatechin gallate) modified black phosphorus quantum dots (BPQDs) as therapeutic nanoplatforms for MIDBW to achieve the synergistic functions of NIR (near-infrared)-response, ROS-generation, sterilization, and promoting wound healing. The electron spin resonance results revealed that EGCG-BPQDs@H had a more vital photocatalytic ability to produce singlet oxygen than BPQDs@H. The inhibition results indicated an effective bactericidal rate of 88.6% against MRSA. Molecular biology analysis demonstrated that EGCG-BPQDs significantly upregulated CD31 nearly fourfold and basic fibroblast growth factor (bFGF) nearly twofold, which were beneficial for promoting the proliferation of vascular endothelial cells and skin epidermal cells. Under NIR irradiation, EGCG-BPQDs hydrogel (EGCG-BPQDs@H) treated MIDBW area could rapidly raise temperature up to 55 °C for sterilization. The MIBDW closure rate of rats after 21 days of treatment was 92.4%, much better than that of 61.1% of the control group. The engineered EGCG-BPQDs@H were found to promote MIDBW healing by triggering the PI3K/AKT and ERK1/2 signaling pathways, which could enhance cell proliferation and differentiation. In addition, intravenous circulation experiment showed good biocompatibility of EGCG-BPQDs@H. No significant damage to major organs was observed in rats. Conclusions The obtained results demonstrated that EGCG-BPQDs@H achieved the synergistic functions of photocatalytic property, photothermal effects and promoted wound healing, and are promising multifunctional nanoplatforms for MIDBW healing in diabetics. Graphical Abstract


2016 ◽  
Vol 27 (50) ◽  
pp. 505204 ◽  
Author(s):  
Wei Wang ◽  
Xinyue Niu ◽  
Haolei Qian ◽  
Liao Guan ◽  
Ming Zhao ◽  
...  

2018 ◽  
Vol 6 (19) ◽  
pp. 8886-8894 ◽  
Author(s):  
Nianqing Fu ◽  
Chun Huang ◽  
Peng Lin ◽  
Mingshan Zhu ◽  
Tao Li ◽  
...  

Dual-functional black phosphorus quantum dot electron selective layer was designed for plastic perovskite solar cells. The efficient electron extraction and improved perovskite film quality contributed to the reasonably high efficiency.


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