In this work we present the first results on a 'label-free' DNA analysis system based on hydrogenated amorphous silicon (a-Si:H) thin film sensors. The detection mechanism is based on absorbance measurements performed on DNA molecules in a buffer solution. The experiments made with single-stranded 30-mer DNA at different concentrations showed an excellent linearity over three orders of magnitude. The extrapolated minimum quantity (expressed as concentration - optical path product) detectable by our set-up was 2 nmol×cm, limited by short term variations of the UV source intensity. Furthermore, relying on the hypo-chromic effect it is possible to distinguish between single- and double-stranded DNA chains. This was observed performing DNA hybridization experiment on a functionalized glass substrate.
Label-free DNA analysis using a-Si:H UV sensors / D. Caputo; G. de Cesare; A. Nascetti; C. Guiducci; B. Riccò. - STAMPA. - (2005), pp. 254-256. (Intervento presentato al convegno ICST 2005, International Conference on Sensing Technology (IEEE), tenutosi a Palmerston North - New Zealand nel November 2005).
Label-free DNA analysis using a-Si:H UV sensors
GUIDUCCI, CARLOTTA;RICCO', BRUNO
2005
Abstract
In this work we present the first results on a 'label-free' DNA analysis system based on hydrogenated amorphous silicon (a-Si:H) thin film sensors. The detection mechanism is based on absorbance measurements performed on DNA molecules in a buffer solution. The experiments made with single-stranded 30-mer DNA at different concentrations showed an excellent linearity over three orders of magnitude. The extrapolated minimum quantity (expressed as concentration - optical path product) detectable by our set-up was 2 nmol×cm, limited by short term variations of the UV source intensity. Furthermore, relying on the hypo-chromic effect it is possible to distinguish between single- and double-stranded DNA chains. This was observed performing DNA hybridization experiment on a functionalized glass substrate.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
