Fabrication of hybrid photodiode systems: BODIPY decorated cyclotriphosphazene covalently grafted graphene oxides

2020 ◽  
Vol 7 (16) ◽  
pp. 2920-2931
Author(s):  
Emrah Özcan ◽  
Burcu Topaloğlu Aksoy ◽  
Esra Tanrıverdi Eçik ◽  
Ayşegül Dere ◽  
Abdulkerim Karabulut ◽  
...  

Combination of graphene sheets with various organic/inorganic functional groups could enhance the applications of graphene-based hybrid materials.

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 624
Author(s):  
Cintya Dharmayanti ◽  
Todd A. Gillam ◽  
Manuela Klingler-Hoffmann ◽  
Hugo Albrecht ◽  
Anton Blencowe

Synthetic polypeptides and polymer-peptide hybrid materials have been successfully implemented in an array of biomedical applications owing to their biocompatibility, biodegradability and ability to mimic natural proteins. In addition, these materials have the capacity to form complex supramolecular structures, facilitate specific biological interactions, and incorporate a diverse selection of functional groups that can be used as the basis for further synthetic modification. Like conventional synthetic polymers, polypeptide-based materials can be designed to respond to external stimuli (e.g., light and temperature) or changes in the environmental conditions (e.g., redox reactions and pH). In particular, pH-responsive polypeptide-based systems represent an interesting avenue for the preparation of novel drug delivery systems that can exploit physiological or pathological pH variations within the body, such as those that arise in the extracellular tumour microenvironment, intracellularly within endosomes/lysosomes, or during tissue inflammation. Here, we review the significant progress made in advancing pH-responsive polypeptides and polymer-peptide hybrid materials during the last five years, with a particular emphasis on the manipulation of ionisable functional groups, pH-labile linkages, pH-sensitive changes to secondary structure, and supramolecular interactions.


2021 ◽  
Vol 22 (2) ◽  
pp. 515
Author(s):  
Jaroslaw Szczepaniak ◽  
Joanna Jagiello ◽  
Mateusz Wierzbicki ◽  
Dorota Nowak ◽  
Anna Sobczyk-Guzenda ◽  
...  

The development of nanotechnology based on graphene and its derivatives has aroused great scientific interest because of their unusual properties. Graphene (GN) and its derivatives, such as reduced graphene oxide (rGO), exhibit antitumor effects on glioblastoma multiforme (GBM) cells in vitro. The antitumor activity of rGO with different contents of oxygen-containing functional groups and GN was compared. Using FTIR (fourier transform infrared) analysis, the content of individual functional groups (GN/exfoliation (ExF), rGO/thermal (Term), rGO/ammonium thiosulphate (ATS), and rGO/ thiourea dioxide (TUD)) was determined. Cell membrane damage, as well as changes in the cell membrane potential, was analyzed. Additionally, the gene expression of voltage-dependent ion channels (clcn3, clcn6, cacna1b, cacna1d, nalcn, kcne4, kcnj10, and kcnb1) and extracellular receptors was determined. A reduction in the potential of the U87 glioma cell membrane was observed after treatment with rGO/ATS and rGO/TUD flakes. Moreover, it was also demonstrated that major changes in the expression of voltage-dependent ion channel genes were observed in clcn3, nalcn, and kcne4 after treatment with rGO/ATS and rGO/TUD flakes. Furthermore, the GN/ExF, rGO/ATS, and rGO/TUD flakes significantly reduced the expression of extracellular receptors (uPar, CD105) in U87 glioblastoma cells. In conclusion, the cytotoxic mechanism of rGO flakes may depend on the presence and types of oxygen-containing functional groups, which are more abundant in rGO compared to GN.


Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 802 ◽  
Author(s):  
Chii-Rong Yang ◽  
Shih-Feng Tseng ◽  
Yu-Ting Chen

The chemical oxidation method can be used to mass-produce graphene oxides (GOs) from highly oriented pyrolytic graphite. However, numerous oxygen-containing functional groups (hydroxyl, epoxy, carbonyl, etc.) exist in typical GO surfaces, resulting in serious electrical losses. Hence, GO must be processed into reduced graphene oxide (rGO) by the removal of most of the oxygen-containing functional groups. This research concentrates on the reduction efficiency of GO films that are manufactured using atmospheric-pressure and continuous plasma irradiation. Before and after sessions of plasma irradiation with various irradiation times, shelters, and working distances, the surface, physical, and electrical characteristics of homemade GO and rGO films are measured and analyzed. Experimental results showed that the sheet resistance values of rGO films with silicon or quartz shelters were markedly lower than those of GO films because the rGO films were mostly deprived of oxygen-containing functional groups. The lowest sheet resistance value and the largest carbon-to-oxygen ratio of typical rGO films were approximately 90 Ω/sq and 1.522, respectively. The intensity of the C–O bond peak in typical rGO films was significantly lower than that in GO films. Moreover, the intensity of the C–C bond peak in typical rGO films was considerably higher than that in GO films.


2018 ◽  
Vol 271 ◽  
pp. 142-150 ◽  
Author(s):  
Ju Sun ◽  
Xia Liu ◽  
Shengxia Duan ◽  
Ahmed Alsaedi ◽  
Fengsong Zhang ◽  
...  

ACS Nano ◽  
2011 ◽  
Vol 5 (4) ◽  
pp. 3052-3058 ◽  
Author(s):  
Leilei Tian ◽  
Parambath Anilkumar ◽  
Li Cao ◽  
Chang Yi Kong ◽  
Mohammed J. Meziani ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Dinesh K. Patel ◽  
Yu-Ri Seo ◽  
Ki-Taek Lim

Stimuli-responsive materials, also known as smart materials, can change their structure and, consequently, original behavior in response to external or internal stimuli. This is due to the change in the interactions between the various functional groups. Graphene, which is a single layer of carbon atoms with a hexagonal morphology and has excellent physiochemical properties with a high surface area, is frequently used in materials science for various applications. Numerous surface functionalizations are possible for the graphene structure with different functional groups, which can be used to alter the properties of native materials. Graphene-based hybrids exhibit significant improvements in their native properties. Since functionalized graphene contains several reactive groups, the behavior of such hybrid materials can be easily tuned by changing the external conditions, which is very useful in biomedical applications. Enhanced cell proliferation and differentiation of stem cells was reported on the surfaces of graphene-based hybrids with negligible cytotoxicity. In addition, pH or light-induced drug delivery with a controlled release rate was observed for such nanohybrids. Besides, notable improvements in antimicrobial activity were observed for nanohybrids, which demonstrated their potential for biomedical applications. This review describes the physiochemical properties of graphene and graphene-based hybrid materials for stimuli-responsive drug delivery, tissue engineering, and antimicrobial applications.


2017 ◽  
Vol 19 (45) ◽  
pp. 30895-30913 ◽  
Author(s):  
Murugan Lalitha ◽  
Senthilkumar Lakshmipathi

The complete reduction of graphene oxide is difficult to achieve, and hence oxygen-containing functional groups do exist in graphene, along with structural defects.


2014 ◽  
Vol 894 ◽  
pp. 8-12
Author(s):  
Myeong Jin Kim ◽  
Ki Ho Kim ◽  
Myeong Yeol Yoo ◽  
Joo Heon Kim

Two types of graphene/MnO2 composites were synthesized by different reaction procedures. R-GO/MnO2 was synthesized as follows: first, nanoneedle MnO2 was formed on the GO sheets using various functional groups (GO/MnO2). In the second stage, GO/MnO2 was reduced to graphene/MnO2 (R-GO/MnO2) via the dipping method. rGO/MnO2 was synthesized using a different reaction order: first, graphene oxide was reduced to graphene and nanoneedle MnO2 was formed on graphene sheets. Characterization indicated that the nanoneedle MnO2 structures in the R-GO/MnO2 composite were homogeneously dispersed on graphene sheets, whereas MnO2 in the rGO/MnO2 composite formed aggregates due to absence of functional groups. The R-GO/MnO2 electrode exhibited a specific capacitance as high as 327.5 Fg-1at 10 mVs-1, which was higher than that of the rGO/MnO2 electrode (229.9 Fg-1). It is anticipated that the formation of nanoneedle MnO2 on the GO surface following the reduction procedure could be a promising fabrication method for supercapacitor electrodes.


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