title: Highly Uniform Gold Nanobipyramids for Ultrasensitive Colorimetric Detection of Influenza Virus.
abstract: Gold nanoparticles (AuNPs) have been frequently utilized for the construction of diverse colorimetric biosensors. Normally, AuNPs with sharp edges could have better sensitivity. However, the poor monodipersity of AuNPs with sharp edges seriously confines their utility for colorimetric biosensing. Herein, we demonstrate the utility of highly uniform gold nanobipyramids (Au NBPs) for ultrasensitive colorimetric detection of H5N1virus. The proposed method is based on the fact that alkaline phosphatase (ALP) could catalyze the decomposition of 4-aminophenyl phosphate (4-APP) to generate 4-aminophenol (4-AP), which would then reduce silver nitrate to metal silver and then deposited on Au NBPs. The metal silver shell coated on the Au NBPs changed the refractive index of gold and thus resulted in a blue shift of longitudinal localized surface plasmon resonance (LSPR) and accompanied a vivid color change. This method exhibited a higher sensitivity than that of other Au NPs such as gold nanorods due to the high-index-faceted on the tips of the Au NBPs. This method was used to detect the activity of ALP. It exhibited a linear range of 0.1-5 mU/mL with a limit of detection (LOD) of 0.086 mU/mL. Finally, the proposed method was used in immunoassay to detect H5N1virus. The results showed that the corresponding linear range for the detection of H5N1virus antigen was 0.001-2.5 ng/mL, and the LOD was determined to be 1 pg/mL, which is more sensitive than those in most of the colorimetric biosensors reported previously.
authors.affiliation: Institute of Nanomedicine and Nanobiosensing, Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University , Fuzhou, 350116, China.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Xu
authors.affiliation: Institute of Nanomedicine and Nanobiosensing, Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University , Fuzhou, 350116, China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Ouyang
authors.affiliation: Institute of Nanomedicine and Nanobiosensing, Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University , Fuzhou, 350116, China.
authors.forename: Peisi
authors.initials: P
authors.lastname: Xie
authors.affiliation: Institute of Nanomedicine and Nanobiosensing, Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University , Fuzhou, 350116, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Institute of Nanomedicine and Nanobiosensing, Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University , Fuzhou, 350116, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Qiu
authors.affiliation: Institute of Nanomedicine and Nanobiosensing, Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University , Fuzhou, 350116, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Institute of Nanomedicine and Nanobiosensing, Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University , Fuzhou, 350116, China.
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen
authors.affiliation: Institute of Nanomedicine and Nanobiosensing, Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University , Fuzhou, 350116, China.
authors.forename: Longhua
authors.identifier: 0000-0003-0706-0973
authors.initials: L
authors.lastname: Guo
mesh_terms: D000469:Alkaline Phosphatase / Q000737:chemistry / Q000378:metabolism; D000627:Aminophenols / Q000737:chemistry; D003124:Colorimetry; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay; D053124:Influenza A Virus, H5N1 Subtype / Q000302:isolation & purification*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D000627:Aminophenols; D006046:Gold; D000469:Alkaline Phosphatase; C026729:4-aminophenol