Département de chimie moléculaire

For the efficient surface plasmon resonance (SPR)-based DNA assay researching, signal amplification tactics were absolutely necessary. In this work, a sensitive SPR-DNA sensor was developed by employing in situ synthesis of copper nanoparticles (CuNPs) templated by poly-T sequences DNA from terminal deoxynucleotidyl transferase (TdT)-mediated extension, and synergistically with nano-effect deposition as the mass relay. The objective of this strategy was manifold: firstly, tDNA hybridized with the optimal designed probes to active the TdT-mediated DNA extension onto the surface of SPR chip, resulted a long poly-T sequences ssDNA chain in dsDNA terminal onto surface of gold chip and characterized by SPR signal amplitudes. Secondly, copper ion (Cu2+) adsorbed into the skeleton of poly-T sequences DNA, with the aid of ascorbic acid (VC) to achieve the Cu2+ redn., copper nanostructures (CuNPs) was synchronously generated onto the single nucleotide chain anchoring in dsDNA derivs. and the formation was featured by transmission electron micrographs (TEM) and electrochem. Lastly, dsDNA-complexed CuNPs (CuNPs@dsDNA) triggered the final signal amplification via real-time conversion of the additive catechol violet (CV) into oligomer or chelation pptn. by CuNPs-tagged reporters. With the proposed setups, a precise and replicable DNA sensing platform for specific target oligo was obtained with a detection limit down to 3.21 femtomolar, demonstrating a beneficial overlapping exploitation of nanomaterials and biochem. reaction as unique SPR infrastructure. Such triple-amplification strategic setups, the possibility of various methods abutment and biocompatibility wt. reactor was amassed and adapted to more biol. detection field. [on SciFinder(R)]