title: Enzyme-free colorimetric bioassay based on gold nanoparticle-catalyzed dye decolorization.
abstract: A novel, enzyme-free and aptamer-based colorimetric platform for protein detection has been developed, which takes advantage of aptamer-functionalized magnetic beads (MBs) for target capture, concentration and separation, and aptamer-conjugated gold nanoparticle (AuNP)-catalyzed color bleaching reaction of methyl orange (MO) to generate the colorimetric signals. It was demonstrated that the proposed colorimetric sensing strategy enables simple, cost-effective, sensitive and specific thrombin detection without the use of any enhancing solutions and enzymes. Herein, by naked eye observation, we can detect the human thrombin with a detection limit of approximately 320 pM, which can be further decreased to 30 pM with the help of a UV-vis instrument. In addition, this method also works for targets with two or more binding sites.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, Jiangsu, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Weibing
authors.initials: W
authors.lastname: Qiang
authors.forename: Jingjuan
authors.initials: J
authors.lastname: Xu
authors.forename: Danke
authors.initials: D
authors.lastname: Xu
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D001391:Azo Compounds / Q000737:chemistry*; D015374:Biosensing Techniques; D002384:Catalysis; D003124:Colorimetry; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D013917:Thrombin / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D001391:Azo Compounds; C100258:methyl orange; D006046:Gold; D013917:Thrombin