title: Label-free electrochemical genosensor based on mesoporous silica thin film.
abstract: A novel label-free electrochemical strategy for nucleic acid detection was developed by using gold electrodes coated with mesoporous silica thin films as sensing interface. The biosensing approach relies on the covalent attachment of a capture DNA probe on the surface of the silica nanopores and further hybridization with its complementary target oligonucleotide sequence, causing a diffusion hindering of an Fe(CN)6 (3-/4-) electrochemical probe through the nanochannels of the mesoporous film. This DNA-mesoporous silica thin film-modified electrodes allowed sensitive (91.7 A/M) and rapid (45 min) detection of low nanomolar levels of synthetic target DNA (25 fmol) and were successfully employed to quantify the endogenous content of Escherichia coli 16S ribosomal RNA (rRNA) directly in raw bacterial lysate samples without isolation or purification steps. Moreover, the 1-month stability demonstrated by these biosensing devices enables their advanced preparation and storage, as desired for practical real-life applications. Graphical abstract Mesoporous silica thin films as scaffolds for the development of novel label-free electrochemical genosensors to perform selective, sensitive and rapid detection of target oligonucleotide sequences. Application towards E. coli determination.
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Tunis El Manar, Rue Béchir Salem Belkheria, Tunis El-Manar, 2092, Tunis, Tunisia.
authors.forename: Maroua
authors.initials: M
authors.lastname: Saadaoui
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28040, Madrid, Spain.
authors.forename: Iñigo
authors.initials: I
authors.lastname: Fernández
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28040, Madrid, Spain.
authors.forename: Gema
authors.initials: G
authors.lastname: Luna
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28040, Madrid, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Díez
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28040, Madrid, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Campuzano
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Tunis El Manar, Rue Béchir Salem Belkheria, Tunis El-Manar, 2092, Tunis, Tunisia.
authors.forename: Noureddine
authors.initials: N
authors.lastname: Raouafi
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28040, Madrid, Spain. alfredosanchez@quim.ucm.es.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Sánchez
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28040, Madrid, Spain. pingarro@quim.ucm.es.
authors.forename: José M
authors.initials: JM
authors.lastname: Pingarrón
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28040, Madrid, Spain. rvillalonga@quim.ucm.es.
authors.forename: Reynaldo
authors.initials: R
authors.lastname: Villalonga
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D004247:DNA / Q000032:analysis / Q000235:genetics; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004867:Equipment Design; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D006801:Humans; D061925:Immobilized Nucleic Acids / Q000737:chemistry* / Q000235:genetics; D009693:Nucleic Acid Hybridization / Q000379:methods*; D016062:Porosity; D012329:RNA, Bacterial / Q000032:analysis* / Q000235:genetics; D012335:RNA, Ribosomal / Q000032:analysis* / Q000235:genetics; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D061925:Immobilized Nucleic Acids; D012329:RNA, Bacterial; D012335:RNA, Ribosomal; D012822:Silicon Dioxide; D004247:DNA
keywords: 16S rRNA; Cyclic voltammetry; DNA; E. coli; Genosensor; Mesoporous silica film