title: Simple diazonium chemistry to develop specific gene sensing platforms.
abstract: A simple strategy for covalent immobilizing DNA sequences, based on the formation of stable diazonized conducting platforms, is described. The electrochemical reduction of 4-nitrobenzenediazonium salt onto screen-printed carbon electrodes (SPCE) in aqueous media gives rise to terminal grafted amino groups. The presence of primary aromatic amines allows the formation of diazonium cations capable to react with the amines present at the DNA capture probe. As a comparison a second strategy based on the binding of aminated DNA capture probes to the developed diazonized conducting platforms through a crosslinking agent was also employed. The resulting DNA sensing platforms were characterized by cyclic voltammetry, electrochemical impedance spectroscopy and spectroscopic ellipsometry. The hybridization event with the complementary sequence was detected using hexaamineruthenium (III) chloride as electrochemical indicator. Finally, they were applied to the analysis of a 145-bp sequence from the human gene MRP3, reaching a detection limit of 210 pg μL(-1).
authors: Department of Analytical Chemistry, Universidad Autónoma de Madrid, 28049 Madrid, Spain. Electronic address: monica.revenga@uam.es.
authors: M
authors: M
authors: Revenga-Parra
authors: Department of Analytical Chemistry, Universidad Autónoma de Madrid, 28049 Madrid, Spain. Electronic address: tania.garcia@uam.es.
authors: T
authors: T
authors: García-Mendiola
authors: Department of Analytical and Food Chemistry, Universidad de Vigo, 36310 Vigo, Pontevedra, Spain. Electronic address: vichu@uvigo.es.
authors: J
authors: J
authors: González-Costas
authors: Department of Analytical and Food Chemistry, Universidad de Vigo, 36310 Vigo, Pontevedra, Spain. Electronic address: eromero@uvigo.es.
authors: E
authors: E
authors: González-Romero
authors: Department of Applied Physics, Universidad Autónoma de Madrid, 28049 Madrid, Spain. Electronic address: antonio.garciamarin@uam.es.
authors: A García
authors: AG
authors: Marín
authors: Department of Applied Physics, Universidad Autónoma de Madrid, 28049 Madrid, Spain. Electronic address: joseluis.pau@uam.es.
authors: J L
authors: JL
authors: Pau
authors: Department of Analytical Chemistry, Universidad Autónoma de Madrid, 28049 Madrid, Spain. Electronic address: felix.pariente@uam.es.
authors: F
authors: F
authors: Pariente
authors: Department of Analytical Chemistry, Universidad Autónoma de Madrid, 28049 Madrid, Spain; IMDEA Nanociencia, Madrid, Spain. Electronic address: encarnacion.lorenzo@uam.es.
authors: E
authors: E
authors: Lorenzo
mesh_terms: D015374:Biosensing Techniques; D002244:Carbon / Q000737:chemistry; D004247:DNA / Q000032:analysis*; D015342:DNA Probes / Q000737:chemistry; D003979:Diazonium Compounds / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D006801:Humans; D057230:Limit of Detection; D009693:Nucleic Acid Hybridization / Q000379:methods*
chemical_list: D015342:DNA Probes; D003979:Diazonium Compounds; C035176:benzenediazonium; D002244:Carbon; D004247:DNA
keywords: DNA sensing platform; Diazonium chemistry; Real DNA sample detection