Target-driven self-assembly of stacking deoxyribonucleic acids for highly sensitive assay of proteins.
In this paper, we report a new signal amplification strategy for highly sensitive and enzyme-free method to assay proteins based on the target-driven self-assembly of stacking deoxyribonucleic acids (DNA) on an electrode surface. In the sensing procedure, binding of target protein with the aptamer probe is used as a starting point for a scheduled cycle of DNA hairpin assembly, which consists of hybridization, displacement and target regeneration. Following numbers of the assembly repeats, a great deal of DNA duplexes can accordingly be formed on the electrode surface, and then switch on a succeeding propagation of self-assembled DNA concatemers that provide further signal enhancement. In this way, each target binding event can bring out two cascaded DNA self-assembly processes, namely, stacking DNA self-assembly, and therefore can be converted into remarkably intensified electrochemical signals by associating with silver nanoparticle-based readout. Consequently, highly sensitive detection of target proteins can be achieved. Using interferon-gamma as a model, the assay method displays a linear range from 1 to 500 pM with a detection limit of 0.57 pM, which is comparable or even superior to other reported amplified assays. Moreover, the proposed method eliminates the involvement of any enzymes, thereby enhancing the feasibility in clinical diagnosis.
Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, China.
Ya
Y
Cao
Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, China; Shanghai Key Laboratory of Bio-Energy Crops, Shanghai University, Shanghai 200444, China.
Weiwei
W
Chen
Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, China.
Peng
P
Han
Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, China.
Zhuxin
Z
Wang
Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, China; Department of Biochemistry and State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, China. Electronic address: genxili@nju.edu.cn.
Genxi
G
Li
D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000378:metabolism; D015374:Biosensing Techniques; D004247:DNA / Q000138:chemical synthesis / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D007371:Interferon-gamma / Q000032:analysis*; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry; D012834:Silver / Q000737:chemistry
D052157:Aptamers, Nucleotide; D012834:Silver; D007371:Interferon-gamma; D004247:DNA
Aptamer; Electrochemical; Interferon-gamma; Self-assembly; Signal amplification