title: Self-assembled monolayers of mercaptobenzoic acid and magnetite nanoparticles as an efficient support for development of tuberculosis genosensor.
abstract: In this work, a genosensor for the electrochemical detection of genomic DNA from Mycobacterium tuberculosis was developed. The biosensor is based on self-assembled monolayers of mercaptobenzoic acid (MBA) and magnetite nanoparticles (Fe3O4Nps) on bare gold electrode for immobilization of DNA probe. The aim of this work was the development of a platform based on cysteine-coated magnetic Fe3O4Nps linked via the carboxylate group from MBA to the work electrode surface and subsequently to the DNA probe. The probe-genome interaction was evaluated using a [Fe(CN)6](4-)/[Fe(CN)6](3-) redox pair. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to evaluate the bioelectrochemical behavior of the sensor. Atomic force microscopy images showed Fe3O4Nps immobilized across the electrode surface. The interaction of the sensor with different genome DNA concentrations resulted in changes in the charge transfer resistance, indicating a possible use for tuberculosis detection at low concentrations (detection limit of 6ngμL(-1)).
authors.affiliation: Programa de Pós-Graduação em Bioquímica e Fisiologia, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil.
authors.forename: Maurilia P
authors.initials: MP
authors.lastname: Costa
authors.affiliation: Departamento de Bioquímica, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil.
authors.forename: Cesar A S
authors.initials: CAS
authors.lastname: Andrade
authors.affiliation: Laboratório de Doenças Transmissíveis, Centro de Pesquisas Aggeu Magalhães, 50670-420 Recife, PE, Brazil.
authors.forename: Rosana A
authors.initials: RA
authors.lastname: Montenegro
authors.affiliation: Laboratório de Doenças Transmissíveis, Centro de Pesquisas Aggeu Magalhães, 50670-420 Recife, PE, Brazil.
authors.forename: Fabio L
authors.initials: FL
authors.lastname: Melo
authors.affiliation: Programa de Pós-Graduação em Bioquímica e Fisiologia, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil; Departamento de Bioquímica, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil. Electronic address: m_danielly@yahoo.com.br.
authors.forename: Maria D L
authors.initials: MDL
authors.lastname: Oliveira
mesh_terms: D001565:Benzoates / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D058266:Dielectric Spectroscopy; D055664:Electrochemical Techniques; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D009169:Mycobacterium tuberculosis / Q000737:chemistry / Q000235:genetics; D015345:Oligonucleotide Probes / Q000737:chemistry / Q000235:genetics; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D014376:Tuberculosis / Q000175:diagnosis / Q000235:genetics
chemical_list: D001565:Benzoates; D004269:DNA, Bacterial; D058185:Magnetite Nanoparticles; D015345:Oligonucleotide Probes; D013438:Sulfhydryl Compounds; D003545:Cysteine
keywords: Biosensor; Cyclic voltammetry; Electrochemical impedance spectroscopy; Nanoparticles; Tuberculosis