A colorimetric aptamer biosensor based on cationic polymer and gold nanoparticles for the ultrasensitive detection of thrombin.
A colorimetric assay for the ultrasensitive determination of thrombin based on cationic polymer and gold nanoparticles was presented, in which unmodified gold nanoparticles (AuNPs) was used as probes and 21-mer thrombin-binding aptamer (TBA) as sensing elements. Upon the addition of thrombin, TBA interacted specifically with thrombin to form a G-quadruplex structure. As a result, the conformation change facilitated the cationic polymer, poly(diallyldimethylammonium chloride) (PDDA)-induced AuNP aggregation. Thus, the visible change in color from wine-red to blue-purple was readily seen by the naked eye. The colorimetric sensor could detect thrombin down to 1 pM with high selectivity in the presence of other interferring proteins. Furthermore, the assay was successfully employed to determine thrombin in human serum sample, which suggested its great potential for diagnostic purposes.
Department of Chemistry, Capital Normal University, Beijing 100048, China. Electronic address: czb979216@sina.com.
Zhengbo
Z
Chen
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Yuan
Y
Tan
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Chenmeng
C
Zhang
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Lu
L
Yin
Department of Chemistry, Capital Normal University, Beijing 100048, China.
He
H
Ma
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Nengsheng
N
Ye
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Hong
H
Qiang
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Yuqing
Y
Lin
D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry*; D011095:Polyethylenes / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013917:Thrombin / Q000032:analysis*
D052157:Aptamers, Nucleotide; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; C081676:thrombin aptamer; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D006046:Gold; D013917:Thrombin
Aptamer; Cationic polymer; Colorimetry; Gold nanoparticles; Thrombin