Graphene Oxide as a Nanocarrier for Biochemical Molecules: Current Understanding and Trends

The development of an advanced and efficient drug delivery system with significant improvement in its efficacy and enhanced therapeutic value is one of the critical challenges in modern medicinal biology. The integration of nanomaterial science with molecular and cellular biology has helped in the advancement and development of novel drug delivery nanocarrier systems with precision and decreased side effects. The design and synthesis of nanocarriers using graphene oxide (GO) have been rapidly growing over the past few years. Due to its remarkable physicochemical properties, GO has been extensively used in efforts to construct nanocarriers with high specificity, selectivity, and biocompatibility, and low cytotoxicity. The focus of this review is to summarize and address recent uses of GO-based nanocarriers and the improvements as efficient drug delivery systems. We briefly describe the concepts and challenges associated with nanocarrier systems followed by providing critical examples of GO-based delivery of drug molecules and genes. Finally, the review delivers brief conclusions on the current understanding and prospects of nanocarrier delivery systems.O

Green and non-mechanical method for production of colloidal-size biochar from agriculture waste

Soil is an important source of nutrient and habitat to microflora. During the past 40 years’, the world has lost one-third of its arable land due to an increase in the human population, excessive use of chemical fertilizers, and erosion. There is an urgent need to maintain sustainable approaches in agriculture system. Application of biochar as a soil amendment is a promising approach to improve soil physical, chemical, biological, and hydrological properties. In recent year’s special attention has been focused on pyrolysis condition of biomass, although properties can also be enhanced by the reduction in particle size. Small-size biochar attracts increasing interest due to its unique environmental behavior. This research presents a physical method to modify biochar by ultrasonic radiation to produce colloidal size biochar. Agriculture waste biochar (1 cm) was used as a starting material. We used Malvern sonicator “Hydro 2000MU“ of 20Hz frequency. Biochar (5gram) was added to 100 ml of deionized water and sonicated for 5 hr; after every 15 min of run time, sonicator was stoped for the next 15 min. Please click Additional Files below to see the full abstract

Stability of Zn and Cu nanoparticles studied in aqueous medium by scanning electron microscopy

The stability of nanoparticles in aquatic environment plays an important role for their environmental and biological application. The storage time has strong impact on the stability of zinc and copper nanoparticles (ZnONPs and CuNPs). The effect of the storage time was studied over time and the results showed a change in morphology of synthesized NPs. The time stability study was divided into three parts: short-term (0 - 72 h), medium-term (16 days) and long-term (5 months). In the case of CuNPs the SEM picture revealed the presence of crystal structure. This can be explained as the CuNPs surface layer was oxidized and the crystals on surface are copper oxides. Similar study was conducted on ZnONPs, but in shorter time scale (1 - 3 days). As in the case of CuNPs, ZnONPs showed the same tendency to crystalize. We can conclude that storage time and conditions have a strong impact on the NPs stability

Gold nanoparticles modified screen printed carbon electrode as a tool for detection of TP53

Cancer is one of the most common causes of death in developing countries and in the developed world. The function of the p53 protein plays an important role in the development of cancer. The protein p53 regulates the expression of genes that are responsible for the control of cell growth, apoptosis or for repair of damaged DNA. It t is encoded by the tumor suppressor gene TP53. If this gene mutates, its product will be damaged. It was found that mutations in the TP53 gene is present in more than 50% of cancer cases. Electrochemical biosensors have proved to be a suitable method for the detection of TP53 and also its mutations. Electrochemical deposition of gold nanoparticles on the surface of working electrode increases the active surface area of the sensor, this leads to a more sensitive detection of the TP53 gene and its mutations. By developing an electrochemical biosensor based on gold nanoparticles modified screen printed electrodes, an efficient platform for detecting the TP53 gene in biological samples is obtained

An electrochemical biosensor developed for the online monitoring of H2O2 based on the reduced graphene oxide-cerium dioxide nanocomposite

A biosensor was developed for monitoring H2O2 based on reduced Graphene Oxide-Cerium Oxide (rGO-CeO2) nanocomposite (NC). The NC shows catalytic effect on the electrochemical reduction of H2O2 at 0.3 V. The effect of the NC on the electrochemical reduction of H2O2 was studied by cyclic voltammetry and compared with bare glassy carbon (GC) and GC/r-GO. Moreover, to improve the signal a complex containing copper was incorporated in the dispersion of the nanocomposite which acts as a mediator. It was found that the electrochemical reduction of H2O2 takes place at less negative potential with increased peak current attitude at GC/r-GO-mediator. The developed sensor GC/r-GO-mediator, was applied for the continuous monitoring of H2O2 by chronoamperometry. The applied potential was 0.3 V which results in the enhanced sensitivity of the developed biosensor. The developed biosensor shows good stability, and reproducibility. The reproducibility of the developed electrode was evaluated by calculation of relative standard deviation value 6.77%. The linear range was found to be 3.4 - 23.48 g/ml. Furthermore, limit of detection and limit of quantification were 0.68 g/ml and 2.27 g/ml respectively