title: A new colorimetric platform for ultrasensitive detection of protein and cancer cells based on the assembly of nucleic acids and proteins.
abstract: An amplified colorimetric method has been developed for the detection of protein and cancer cells based on the assembly of nucleic acids and proteins for the first time. In this process, the assembly of nucleic acids was triggered by a biotinylated DNA strand after a sandwich immunoreaction. The biotinylated DNA strand and sandwich immunocomplex were connected by streptavidin. Then, the assembly of biotinylated bovine serum albumin (Biotin-BSA) and streptavidin-horseradish peroxidase (SA-HRP) occurred at a node of the assembled products of nucleic acids through the biotin-streptavidin reaction. Under the catalysis of horseradish peroxidase, 3,3',5,5'-tetramethylbenzidine (TMB) was oxidized by H2O2 and the oxidized product was analyzed by its UV-vis absorbance signal and sensitive colorimetric detection. This colorimetric sensor could not only achieve the quantitative determination of protein by UV-vis absorbance but could also be applied for semiquantitative determination by digital visualization. Using alpha-fetoprotein (AFP) as the model target, this proposed colorimetric method showed a wide linear range from 5 pg/mL to 1 ng/mL with a detection limit of 1.95 pg/mL by the instrument, and even 5 pg/mL target protein could be distinguished simply by the naked eye. This approach was then expanded to detect cancer cells based on the recognition of folic acid receptors that were over-expressed on the cancer cells by folic acid-tethered DNA. More importantly, this strategy can be further used as a universal colorimetric method for the determination of viruses or other proteins by changing the corresponding antibodies.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Chaohui
authors.initials: C
authors.lastname: Chen
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Xinghu
authors.initials: X
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China.
authors.forename: Hanzhong
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China. Electronic address: zhkhe@whu.edu.cn.
authors.forename: Zhike
authors.initials: Z
authors.lastname: He
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D015374:Biosensing Techniques; D001710:Biotin / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D019921:Biotinylation; D004273:DNA, Neoplasm / Q000032:analysis* / Q000737:chemistry; D057809:HEK293 Cells; D006367:HeLa Cells; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet; D019809:Streptavidin / Q000737:chemistry / Q000378:metabolism; D000509:alpha-Fetoproteins / Q000032:analysis* / Q000737:chemistry
chemical_list: D000911:Antibodies, Monoclonal; D004273:DNA, Neoplasm; D000509:alpha-Fetoproteins; D001710:Biotin; D019809:Streptavidin; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase
keywords: Amplification; Assembly; Colorimetric; Protein detection