Showing papers by "S. Sriman Narayanan published in 2012"
TL;DR: The ultimate aim is to focus on the basic aspects and the importance of various signaling and growth factors for tissue engineering, used for tissues that have a poor self healing capacity, such as cartilage, or when defects are too big for the body's capacity to heal itself, suchas large bone defects.
Abstract: Development of bone and cartilage are emerging as prominent techniques in the field of tissue engineering because of the abundance of problems caused by disease, injury and trauma. Bone is the main supporting system of the body, a biocomposite of elements and tissues which is responsible for the excellent tensile and loading strength. Cartilage is an avascular, aneural and alymphatic tissue and does not have regenerative capabilities, so a great amount of assistance is required from outside to repair the defect site. Autografts and allografts are useful in the case of bone defects, but still they require a second surgery from the donor, and transmission of diseases are also possible. The objective of this review is to discuss the approaches that have been taken in bone and cartilage tissue engineering with an emphasis on the cell sources such as embryonic stem cells, adipose derived stem cells, mesenchymal stem cells and progenitor stem cells. A potential scaffold is also important for the mechanical and cellular functions for bone and cartilage regeneration. Awareness will be spanned over different types of scaffolds such as biomaterial scaffolds, nanofibrous scaffolds and hydrogels. The ultimate aim is to focus on the basic aspects and the importance of various signaling and growth factors for tissue engineering, used for tissues that have a poor self healing capacity, such as cartilage, or when defects are too big for the body's capacity to heal itself, such as large bone defects.
46 citations
TL;DR: The results have shown that the gold nanoclusters has reduced the formal potential of Azure A and enhanced the current due to the fast charge transfer kinetics, and the proposed electrode exhibited good stability and reproducibility, and it has the potential application as a sensor for other biologically significant compounds.
32 citations
TL;DR: An amperometric hydrogen peroxide biosensor using a nanobiocomposite based on neutral red modified carbon nanotubes and co-immobilized glucose oxidase and horseradish peroxidase is reported in this article.
Abstract: An amperometric hydrogen peroxide biosensor using a nanobiocomposite based on neutral red modified carbon nanotubes and co-immobilized glucose oxidase and horseradish peroxidase is reported. Modification of the nanobiocomposite electrode with neutral red resulted in a sensitive, low-cost and reliable H2O2 sensor. The use of carbon nanotubes, as the conductive part of the composite, facilitated fast electron transfer rates. The biosensor was characterized for the influence of pH, potential and temperature. A remarkable feature of the biosensor is the detection of H2O2 at low applied potentials where the noise level and interferences are minimal. The sensor has a fast steady-state measuring time of 10 s with a quick response (2 s). The biosensor showed a linear range from 15 nM to 45 mM of H2O2 and a detection limit of 5 nM. Nafion, which is used as a binder, makes the determination free from other electroactive substances. The repeatability, reproducibility, stability and analytical performance of the sensor are very good.
12 citations
TL;DR: In this paper, the activation and deactivation of room temperature ferromagnetic behavior in pure and V doped ZnO(Zn0.95V0.05O) films upon surface functionalization with thiol was investigated with X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), temperature programmed desorption (TPD), and vibrating sample magnetometer (VSM) measurements.
Abstract: In this paper, we report the activation and deactivation of room temperature ferromagnetism in pure and V doped ZnO(Zn0.95V0.05O) films upon surface functionalization with thiol. The thiol functionalized pure ZnO and Zn0.95V0.05O films has been investigated with X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), temperature programmed desorption (TPD) and vibrating sample magnetometer (VSM) measurements. The presence of S 2p3/2 peak about 163.5 eV implies that the formation of Zn-S bonds which in turn leads to the reduction of oxygen vacancies. PL spectra of thiol functionalized pure ZnO and Zn0.95V0.05O films show quenching of visible emission in comparison with the unfunctionalized ZnO films. TPD measurements show that the adsorption of thiol on ZnO surface is stable upto 480 K. On vacuum annealing of the thiol functionalized films above 480 K, desorption starts and gets completely desorbed about 535 K. The room temperature VSM measurements reveal clear signature of ferromagnetic behavior in the functionalized ZnO films. The disappearance of ferromagnetic behavior after vacuum annealing at 550 K confirms the observed ferromagnetic behavior in thiol functionalized ZnO films is due to the strong interaction between the ZnO host and thiol molecules.
2 citations
01 Jan 2012
TL;DR: In this paper, a nonenzymatic amperometric glucose biosensor based on a modified electrode was fabricated by electrochemical derivatization of copper hexacyanoferrate (CuHCF) film at gold nanoparticles (GNP) adsorbed graphite wax composite electrode.
Abstract: A non-enzymatic amperometric glucose biosensor based on a modified electrode was fabricated by electrochemical derivatization of copper hexacyanoferrate (CuHCF) film at gold nanoparticles (GNP) adsorbed graphite wax composite electrode. The modified electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The electrode was also characterized by scanning electron microscopy (SEM) which indicated that the CuHCF particles sized at 100-120 nm were dispersed uniformly on electrode surface. The modified electrode is exemplified towards the non-enzymatic sensing of glucose using cyclic voltammetry and amperometry. A linear calibration curve for glucose determination is obtained in the concentration range from 8.6x10 -6 to 1.2x10 -3 M with a detection limit of 1.3x10 -7 M. The interference of ascorbic acid has been eliminated by coating the electrode surface
1 citations