title: Sandwiching spherical 1,2-dioleoyltrimethylammoniumpropane liposome in gold nanoparticle on solid transducer for electrochemical ultrasensitive DNA detection and transfection.
abstract: Cationic N-[1-(2,3-Dioleoyloxy)propyl]-N,N,N-trimethylammonium propane (DOTAP) liposome is spherically sandwiched in gold nanoparticle (abbreviated as sDOTAP-AuNP) onto a gold electrode surface. The sDOTAP-AuNP is applied for electrochemical label free DNA sensing and Escherichia coli cell transfection for the first time. Complementary target (named as hybridized), non-complementary target (un-hybridized) and single base mismatch target (named as SMM) hybridized surfaces are discriminated sensitively and selectively in presence of [Fe(CN)6](3-/4-). Double strand specific intercalator methylene blue in combination with [Fe(CN)6](3-) is used to enhance target detection limit down to femtomolar concentration. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV) techniques are used for characterizing DNA sensing. High Resolution Transmission Electron Microscopy (HRTEM), Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM) and Dynamic Light Scattering (DLS) techniques are used to confirm the spherical nature of the sDOTAP-AuNP-DNA composite in solution and on the solid surface. DNA on the sDOTAP-ssDNA is transferred by potential stripping method (+0.2V (Ag/AgCl)) into buffer solution containing E. coli cells. The transfection is confirmed by the contrast images for the transfected and non-transfected cell from Confocal Laser Scanning Microscopy (CLSM). The results demonstrate effectiveness of the electrochemical DNA transfection method developed and could be applied for other cells.
authors.affiliation: Molecular Electronics Laboratory, Department of Bioelectronics and Biosensors, Alagappa University, Karaikudi 630003, India.
authors.forename: Jeyaraman
authors.initials: J
authors.lastname: Shankara Narayanan
authors.affiliation: Molecular Electronics Laboratory, Department of Bioelectronics and Biosensors, Alagappa University, Karaikudi 630003, India.
authors.forename: Mohanlal
authors.initials: M
authors.lastname: Bhuvana
authors.affiliation: Molecular Electronics Laboratory, Department of Bioelectronics and Biosensors, Alagappa University, Karaikudi 630003, India. Electronic address: dharumanudhay@yahoo.com.
authors.forename: Venkataraman
authors.initials: V
authors.lastname: Dharuman
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D003217:Conductometry / Q000295:instrumentation*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004926:Escherichia coli / Q000235:genetics*; D006046:Gold / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008839:Microelectrodes; D017422:Sequence Analysis, DNA / Q000295:instrumentation*; D014159:Transducers; D014162:Transfection / Q000295:instrumentation*
chemical_list: D004269:DNA, Bacterial; D008081:Liposomes; D006046:Gold
keywords: DNA biosensing; DOTAP; Electrochemical; Solid surface; Spherical liposome; Transfection