title: Cholesterol biosensors based on oxygen sensing alginate-silica microspheres.
abstract: Cholesterol determination in body is important in diagnosis of diseases like coronary heart disease, arteriosclerosis, diabetes, and obstructive jaundice. This research aims at developing fluorimetric cholesterol biosensors based on self-assembled mesoporous alginate-silica (Algilica) microspheres. For preparing the biosensor, Pt-(II)-octaethylporphine (PtOEP; oxygen sensitive metalloporphyrin) dye has been loaded in the Algilica microspheres using the solvent-mediated precipitation method. Cholesterol oxidase (ChOx) was then covalently conjugated to PtOEP/Algilica microspheres using EDC and NHS reagents. PtOEP dye and enzyme encapsulation, activity and stability were then analyzed. Layer-by-layer self-assembly was finally performed using PAH and PSS polyelectrolytes to minimize leaching of the biosensor components. The prepared biosensor exhibited linearity over a range of 0.77-2.5 mM O(2) (K(SV) : 0.097/mM of O(2) ) obtained using from Stern-Volmer plots. The biosensor response to standard cholesterol displayed a linear analytical range from 1.25 to 10 mM of cholesterol with regression coefficient of 0.996 (1.25-3.75 mM), 0.976 (1.25-6 mM), and 0.959 (1.25-10 mM) and response time of 10 min. Thus, the prepared cholesterol biosensor shows great potential in the diagnosis of hypercholesterolemia.
authors: Department of Biosciences and Bioengineering, IIT Bombay, Powai, Mumbai, India.
authors: Janak
authors: J
authors: Prasad
authors: Abhijeet
authors: A
authors: Joshi
authors: Rahul Dev
authors: RD
authors: Jayant
authors: Rohit
authors: R
authors: Srivastava
mesh_terms: D000464:Alginates / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D002784:Cholesterol / Q000737:chemistry*; D004355:Drug Stability; D004591:Electrophoresis, Polyacrylamide Gel; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010100:Oxygen / Q000032:analysis* / Q000737:chemistry; D012044:Regression Analysis; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013501:Surface-Active Agents / Q000737:chemistry; D014783:Viscosity
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D013501:Surface-Active Agents; D012710:Serum Albumin, Bovine; D020723:Glucuronic Acid; D002784:Cholesterol; D010100:Oxygen