title: Real Colorimetric Thrombin Aptasensor by Masking Surfaces of Catalytically Active Gold Nanoparticles.
abstract: We presented a simple, cost-effective, and ultrasensitive colorimetric approach for visually detecting thrombin by the catalytic amplification of gold nanoparticles (AuNPs) and aptamer-thrombin recognition. Thrombin can be quantified in the presence of catalytic AuNP surface by using color-change time of 4-nitrophenol. Without thrombin, yellow 4-nitrophenol can freely access the surface of AuNP and becomes colorless 4-aminophenol. With the addition of thrombin, aptamer-thrombin with large size interaction masks the partial surfaces of AuNPs, and increases the reduction time of 4-nitrophenol to 4-aminophenol. The maximum number of bound thrombin fully mask the catalytic AuNP surface, and thus 4-nitrophenol cannot approach to AuNP surface, the color of the solution remains yellow. The limit of detection (LOD) of 0.1 nM can be achieved with naked eyes. Of note, the method was further applied for the detection of thrombin in human serum samples, showing the results in agreement with those values obtained in an immobilization buffer by the colorimetric method.
authors.affiliation: Department of Chemistry, Capital Normal University , Beijing 100048, China.
authors.forename: Zhengbo
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Capital Normal University , Beijing 100048, China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Tan
authors.affiliation: Department of Chemistry, Capital Normal University , Beijing 100048, China.
authors.forename: Liangyu
authors.initials: L
authors.lastname: Hu
authors.affiliation: Department of Chemistry, Capital Normal University , Beijing 100048, China.
authors.forename: Yimeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Capital Normal University , Beijing 100048, China.
authors.forename: Shaoxiong
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Capital Normal University , Beijing 100048, China.
authors.forename: Fanyi
authors.initials: F
authors.lastname: Lv
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000032:analysis*; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D002417:Cattle; D003116:Color; D003124:Colorimetry / Q000379:methods*; D005453:Fluorescence; D054856:G-Quadruplexes; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D052157:Aptamers, Nucleotide; C081676:thrombin aptamer; D006046:Gold
keywords: 4-nitrophenol; aptamer; colorimetry; signal amplification; thrombin