Magnetic nanoparticle decorated graphene based electrochemical nanobiosensor for H2O2 sensing using HRP

To utilize synergetic effect of graphene's higher conductivity and magnetic nanoparticles biocompatibility, an electrochemical nanobiosensor is constructed based on magnetic nanoparticle decorated graphene (MRGO) using Horseradish peroxidase (HRP) for H2O2 sensing. Sensors based on magnetic nanoparticles (MNP) and reduced graphene oxide (RGO) are studied for comparison. MNP, RGO and MRGO were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). XRD studies have confirmed successful synthesis of Fe3O4 MNPs, RGO and MRGO. TEM micrographs revealed uniform decoration of MNPs on graphene. FTIR confirmed the immobilization of HRP on MNP, RGO and MRGO. The MRGO based sensor exhibited higher sensitivity (48.08 mu A mu M-1 cm(-2)) compared to MNP (39.08 mu A mu M-1 cm(-2)) and RGO (41.08 mu A mu M-1 cm(-2)) based biosensors. (C) 2018 Elsevier B.V. All rights reserved

Advanced glycation end products (AGEs) in diabetic complications

Hyperglycemic condition in diabetes accelerates formation of advanced glycation end products (AGEs) that are formed as a result of series of reaction between reducing sugars and proteins. Accumulation of AGEs has been implicated in development of insulin resistance as well as in the pathogenesis of diabetic complications. The principal mechanism by which AGEs render harmful effects is through interaction with cell bound receptors. Certain receptors like AGE-R1 are involved in degradation of AGEs, while certain other receptors like receptor for AGE (RAGE) bring about counter effects exacerbating the situation. Accumulation of diverse AGEs, synergistically down regulate AGE-R1 while up regulate RAGE causing vicious cycle leading to enhanced formation and further accumulation of AGEs. In this article we discuss the formation of heterogeneous AGEs, importance of detection and quantification of AGEs, biological degradation of AGEs via different receptors, AGE-RAGE and its role in proinflammatory signaling, AGE mediated diabetic vascular complications such as nephropathy, retinopathy, neuropathy, cardiovascular and cerebrovascular diseases and finally the biological inhibition of AGEs is discussed along with chemical inhibitors for AGEs and natural products in AGE inhibition as a measure for the prevention of diabetic complications