title: Iodide-Responsive Cu-Au Nanoparticle-Based Colorimetric Platform for Ultrasensitive Detection of Target Cancer Cells.
abstract: Colorimetric analysis is promising in developing facile, fast, and point-of-care cancer diagnosis techniques, but the existing colorimetric cancer cell assays remain problematic because of dissatisfactory sensitivity as well as complex probe design or synthesis. To solve the problem, we here present a novel colorimetric analytical strategy based on iodide-responsive Cu-Au nanoparticles (Cu-Au NPs) combined with the iodide-catalyzed H2O2-TMB (3,3,5,5-tetramethylbenzidine) reaction system. In this strategy, bimetallic Cu-Au NPs prepared with an irregular shape and a diameter of ∼15 nm could chemically absorb iodide, thus indirectly inducing colorimetric signal variation of the H2O2-TMB system. By further utilizing its property of easy biomolecule modification, a versatile colorimetric platform was constructed for detection of any target that could cause the change of Cu-Au NPs concentration via molecular recognition. As proof of concept, an analysis of human leukemia CCRF-CEM cells was performed using aptamer Sgc8c-modified Cu-Au NPs as the colorimetric probe. Results showed that Sgc8c-modified Cu-Au NPs successfully achieved a simple, label-free, cost-effective, visualized, selective, and ultrasensitive detection of cancer cells with a linear range from 50 to 500 cells/mL and a detection limit of 5 cells in 100 μL of binding buffer. Moreover, feasibility was demonstrated for cancer cell analysis in diluted serum samples. The iodide-responsive Cu-Au NP-based colorimetric strategy might not only afford a new design pattern for developing cancer cell assays but also greatly extend the application of the iodide-catalyzed colorimetric system.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Changsha 410082, China.
authors.forename: Xiaosheng
authors.initials: X
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Changsha 410082, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Changsha 410082, China.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: He
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Changsha 410082, China.
authors.forename: Kemin
authors.initials: K
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Changsha 410082, China.
authors.forename: Dinggeng
authors.initials: D
authors.lastname: He
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Changsha 410082, China.
authors.forename: Lv'an
authors.initials: L
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Changsha 410082, China.
authors.forename: Fengzhou
authors.initials: F
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Changsha 410082, China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Lei
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Changsha 410082, China.
authors.forename: Jinlu
authors.initials: J
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Changsha 410082, China.
authors.forename: Yanru
authors.initials: Y
authors.lastname: Yu
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D001560:Benzidines / Q000737:chemistry; D002384:Catalysis; D045744:Cell Line, Tumor; D003124:Colorimetry; D003300:Copper / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D007454:Iodides / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D009369:Neoplasms / Q000175:diagnosis; D010084:Oxidation-Reduction; D019095:Point-of-Care Systems
chemical_list: D052157:Aptamers, Nucleotide; D001560:Benzidines; D007454:Iodides; C021758:3,3',5,5'-tetramethylbenzidine; D006046:Gold; D003300:Copper; D006861:Hydrogen Peroxide