Fabrication of Sensitive Electrochemical Quantum-Dot Modified Biosensor for Detection of Apolipoprotein B-100

A quantum dot-electrode system was developed which allows the sensitive detection of apolipoprotein B-100 (apoB-100) specific probe oligonucleotide. The colloidal semiconductive CdS quantum dots attached to gold bychemisorption via a formation of thiol self-assembled monolayer SAMs. The QDs assembly cause an improvment infundamental characteristics of the electrode interface in terms of electroactive surface area, diffusion coefficient andelectron transfer kinetics. This QDs modified electrode has been utilized as a transducer surface for covalentimmobilization of apolipoprotein B-100 specific probe oligonucleotide, detection of DNA synthesis and DNAhybridization. The sensing characteristics of this biosensor offer a potential for detection of target oligonucleotide at aconcentration as low as 3×10-17M. The quantitative results are documented by a calibration experiment over aconcentration range of 10-16-10-6 M target DNA.

کلیدواژه ها:

CdS quantum dot ، Self-assembly ، DNA biosensor ، DNA hybridization ، Apolipoprotein B-100 gene