Nanografted monolayers (NAMs) of DNA, show novel physico-chemical properties, that make them ideally suited for advanced biosensing applications. In comparison with alternative solid-phase techniques for diagnostic DNA detection, NAMs can be distinguished because of their small size and by the high homogeneity of the DNA surface coverage. These two properties favor the extreme miniaturization and ultrasensitivity in high-throughput biosensing devices. The systematic use of NAMs for quantitative DNA (and protein) detection has so far suffered from the lack of a control on key fabrication parameters, such as the ss- or ds-DNA surface coverage. Here we report on a combined experimental-computational study that allows to estimate the surface density of the grafted DNA by analyzing the sample mechanical response, that is the DNA patch height vs. applied tip load curves. It is shown that the same analysis scheme can be used to detect the occurrence of hybridization with complementary strands in solution and estimate its efficiency. Thanks to these quantitative relationships it is possible to use a single AFM-based setup to: (i) fabricate a DNA NAM, (ii) control the DNA surface coverage, (iii) characterize its level of hybridization helping the design of NAMs with pre-determined fabrication parameters.

Hybridization in nanostructured DNA monolayers probed by AFM: theory versus experiment

Casalis, Loredana
;
De Simone, Antonio;
2012

Abstract

Nanografted monolayers (NAMs) of DNA, show novel physico-chemical properties, that make them ideally suited for advanced biosensing applications. In comparison with alternative solid-phase techniques for diagnostic DNA detection, NAMs can be distinguished because of their small size and by the high homogeneity of the DNA surface coverage. These two properties favor the extreme miniaturization and ultrasensitivity in high-throughput biosensing devices. The systematic use of NAMs for quantitative DNA (and protein) detection has so far suffered from the lack of a control on key fabrication parameters, such as the ss- or ds-DNA surface coverage. Here we report on a combined experimental-computational study that allows to estimate the surface density of the grafted DNA by analyzing the sample mechanical response, that is the DNA patch height vs. applied tip load curves. It is shown that the same analysis scheme can be used to detect the occurrence of hybridization with complementary strands in solution and estimate its efficiency. Thanks to these quantitative relationships it is possible to use a single AFM-based setup to: (i) fabricate a DNA NAM, (ii) control the DNA surface coverage, (iii) characterize its level of hybridization helping the design of NAMs with pre-determined fabrication parameters.
2012
Settore FIS/07 - Fisica Applicata(Beni Culturali, Ambientali, Biol.e Medicin)
Settore CHIM/02 - Chimica Fisica
ATOMIC-FORCE MICROSCOPY; SINGLE-STRANDED-DNA; DIRECTED IMMOBILIZATION; GOLD SURFACES; SPECTROSCOPY; THICKNESS; DIFFUSION; PROTEINS; FILMS
File in questo prodotto:
File Dimensione Formato  
Nanoscale_2012.pdf

Accesso chiuso

Tipologia: Published version
Licenza: Non pubblico
Dimensione 441.46 kB
Formato Adobe PDF
441.46 kB Adobe PDF   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11384/84085
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 32
  • ???jsp.display-item.citation.isi??? 31
  • OpenAlex ND
social impact