“Anti-Fouling Characteristics of Surface-Confined Oligonucleotide Strands Bioconjugated on Streptavidin Platforms in the Presence of Nanomaterials”

M. MIR; P.J. CAMERON; X. ZHONG; O. AZZARONI; M. ALVAREZ; W. KNOLL

TALANTA

ELSEVIER SCIENCE BV

Año: 2009 vol. 78 p. 1102 - 1106

0039-9140

Thiswork describes our studies on the molecular design of interfacial architectures suitable for DNA sensing which could resist non-specific binding of nanomaterials commonly used as labels for amplifying biorecognition events. We observed that the non-specific binding of bio-nanomaterials to surfaceconfined oligonucleotide strands is highly dependent on the characteristics of the interfacial architecture. Thiolated double stranded oligonucleotide arrays assembled on Au surfaces evidence significant fouling in the presence of nanoparticles (NPs) at the nanomolar level. The non-specific interaction between the oligonucleotide strands and the nanomaterials can be sensitively minimized by introducing streptavidin (SAv) as an underlayer conjugated to the DNA arrays. The role of the SAv layerwas attributed to the significanthydrophilic repulsion between the SAv-modified surface and the nanomaterials in close proximityto the interface, thus conferring outstanding anti-fouling characteristics to the interfacial architecture. These results provide a simple and straightforward strategy to overcome the limitations introduced by the non-specific binding of labels to achieve reliable detection of DNA-based biorecognition events.