title: Chemiluminescence aptasensor for cocaine based on double-functionalized gold nanoprobes and functionalized magnetic microbeads.
abstract: A novel chemiluminescence (CL) aptasensor for highly sensitive detection of small-molecule targets using cocaine as a model analyte was developed in the present study. For the proposed aptasensor, the aptamers were immobilized on the surface of gold nanoparticles (AuNPs) functionalized magnetic microbeads (MB-AuNPs) and then hybridized with the signal DNA on the double-functional gold nanoprobes (DF-AuNPs) modified with horseradish peroxidase (HRP). When cocaine was introduced, a competition for the aptamer between cocaine and the signal DNA occurred and the gold nanoprobes were forced to dissociate from the MB-AuNPs surface based on the structure switching of the aptamer. The CL signals of Luminol-H(2)O(2)-HRP-PIP system were proportional to the concentration of cocaine. A linear range was obtained when the concentrations of cocaine were from 1 × 10(-9) to 1 × 10(-8) M with the detection limit of 0.48 nM (3σ), much lower than those achieved by other methods. This new system can be easily extended to a variety of small-molecules, protein, and tumor cell analysis.
authors.affiliation: College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing, China. liying79307@163.com
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Ji
authors.forename: Bangwei
authors.initials: B
authors.lastname: Liu
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D003042:Cocaine / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry; D008163:Luminescent Measurements / Q000379:methods*; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D052157:Aptamers, Nucleotide; D006046:Gold; D006735:Horseradish Peroxidase; D003042:Cocaine