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 / Caputo, Domenico; DE CESARE, Giampiero; Nascetti, Augusto; C., Guiducci; B., Ricco'. - (2005), pp. 254-257. ( First International Conference on Sensor Technology Palmerston North, New Zealand ).
Label-free DNA analysis using a-Si:H UV sensors
CAPUTO, Domenico;DE CESARE, Giampiero;NASCETTI, Augusto;
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.
