title: An electrochemical genosensor for Salmonella typhi on gold nanoparticles-mercaptosilane modified screen printed electrode.
abstract: In this work, we fabricated a system of integrated self-assembled layer of organosilane 3-mercaptopropyltrimethoxy silane (MPTS) on the screen printed electrode (SPE) and electrochemically deposited gold nanoparticle for Salmonella typhi detection employing Vi gene as a molecular marker. Thiolated DNA probe was immobilized on a gold nanoparticle (AuNP) modified SPE for DNA hybridization assay using methylene blue as redox (electroactive) hybridization indicator, and signal was monitored by differential pulse voltammetry (DPV) method. The modified SPE was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and atomic force microscopy (AFM) method. The DNA biosensor showed excellent performances with high sensitivity and good selectivity. The current response was linear with the target sequence concentrations ranging from 1.0 × 10(-11) to 0.5 × 10(-8)M and the detection limit was found to be 50 (± 2.1)pM. The DNA biosensor showed good discrimination ability to the one-base, two-base and three-base mismatched sequences. The fabricated genosensor could also be regenerated easily and reused for three to four times for further hybridization studies.
authors.affiliation: Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India.
authors.forename: Ritu
authors.initials: R
authors.lastname: Das
authors.affiliation: Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India.
authors.forename: Mukesh K
authors.initials: MK
authors.lastname: Sharma
authors.affiliation: Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India.
authors.forename: Vepa K
authors.initials: VK
authors.lastname: Rao
authors.affiliation: Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India.
authors.forename: B K
authors.initials: BK
authors.lastname: Bhattacharya
authors.affiliation: Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India.
authors.forename: Iti
authors.initials: I
authors.lastname: Garg
authors.affiliation: Department of Chemistry, IIT Kanpur, Kanpur 208016, India.
authors.forename: V
authors.initials: V
authors.lastname: Venkatesh
authors.affiliation: Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India. Electronic address: sanjayupad@rediffmail.com.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Upadhyay
mesh_terms: D015374:Biosensing Techniques; D004269:DNA, Bacterial / Q000032:analysis; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles; D018625:Microscopy, Atomic Force; D009693:Nucleic Acid Hybridization; D012485:Salmonella typhi / Q000235:genetics / Q000302:isolation & purification*; D012821:Silanes / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D004269:DNA, Bacterial; D012821:Silanes; D013438:Sulfhydryl Compounds; D006046:Gold
keywords: Biosensor; DNA; Differential pulse voltammetry; Mercaptopropyl trimethoxy silane; Screen printed electrode