title: Lipid-lipid interactions in aminated reduced graphene oxide interface for biosensing application.
abstract: A label-free biosensor based on antiapolipoprotein B 100 functionalized-aminated reduced graphene oxide interface has been fabricated for detection of low density lipoprotein (LDL or lipid) cholesterol. The aminated reduced graphene oxide (NH2-rGO) based electrode surface is covalently functionalized with antiapolipoprotein B 100 (AAB or lipid) using EDC/NHS coupling chemistry. The lipid-lipid interactions at the NH2-rGO electrode surface have been investigated using electrochemical impedance spectroscopic technique. The structural and morphological investigations of NH2-rGO based immunosensor have been accomplished via transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, UV-visible, and electrochemical techniques. The impedimetric response of the proposed immunosensor shows excellent sensitivity (612 Ω mg(-1) dL cm(-2)), a response time of 250 s, and a low detection limit of 5 mg/dL of LDL molecules. The association, dissociation, and equilibrium rate constants for this immunoelectrode are found to be 1.66 M(-1) s(-1), 0.6 s(-1), and 2.77 M(-1), respectively. The long-term stability and excellent reproducibility of the proposed immunosensor indicates a suitable platform for detection of LDL or lipid molecules. This immunosensor provides an efficient platform for analysis of the antigen-antibody interactions of lipid molecules.
authors.affiliation: Department of Science and Technology Centre on Biomolecular Electronics, Biomedical Instrumentation Section, CSIR-National Physical Laboratory , Dr. K. S. Krishnan Marg, New Delhi, Delhi 110012, India.
authors.forename: Md Azahar
authors.initials: MA
authors.lastname: Ali
authors.forename: K
authors.initials: K
authors.lastname: Kamil Reza
authors.forename: Saurabh
authors.initials: S
authors.lastname: Srivastava
authors.forename: Ved Varun
authors.initials: VV
authors.lastname: Agrawal
authors.forename: Renu
authors.initials: R
authors.lastname: John
authors.forename: Bansi Dhar
authors.initials: BD
authors.lastname: Malhotra
mesh_terms: D000586:Amination; D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D008055:Lipids / Q000032:analysis*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D008055:Lipids; D010087:Oxides; D006108:Graphite