title: Size-dependent modulation of graphene oxide-aptamer interactions for an amplified fluorescence-based detection of aflatoxin B1 with a tunable dynamic range.
abstract: Aflatoxin B1 (AFB1) is a common toxin found in many foods. While AFB1 sensors have been reported, few studies have shown amplified detection with tunable dynamic ranges. We herein report a simple and highly sensitive amplified aptamer-based fluorescent sensor for AFB1, which relies on the ability of nano-graphene oxide (GO) to protect aptamers from nuclease cleavage for amplified detection and on the nanometer size effect of GO to tune the dynamic range and sensitivity. The assay was performed by simply mixing the carboxyl-X-rhodamine (ROX)-labeled AFB1 aptamer, the GO, the nuclease, and the AFB1 samples. Modulating the size of the GO nanosheet resulted in three dynamic ranges, i.e., 12.5 to 312.5 ng mL(-1), 1.0 to 100 ng mL(-1), and 5.0 to 50 ng mL(-1), with corresponding limits of detection of 10.0 ng mL(-1), 0.35 ng mL(-1) and 15.0 ng mL(-1), respectively. The sensor was highly selective against other aflatoxins and common molecules in foods, and its performance was verified in corn samples spiked with known concentration of AFB1.
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. yi-lu@illinois.edu.
authors.forename: JingJing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Institute of Agricultural Quality Standards and Testing Technology Research, Shandong Academy of Agricultural Sciences, Jinan, 250100, People's Republic of China and Department of Chemistry, Key laboratory of Test Technology on Food Quality and Safety of Shandong Province, Jinan, 250100, People's Republic of China.
authors.forename: Zengmei
authors.initials: Z
authors.lastname: Li
authors.affiliation: Institute of Agricultural Quality Standards and Testing Technology Research, Shandong Academy of Agricultural Sciences, Jinan, 250100, People's Republic of China and Department of Chemistry, Key laboratory of Test Technology on Food Quality and Safety of Shandong Province, Jinan, 250100, People's Republic of China.
authors.forename: Shancang
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. yi-lu@illinois.edu.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
mesh_terms: D016604:Aflatoxin B1 / Q000032:analysis*; D052157:Aptamers, Nucleotide; D005453:Fluorescence; D005506:Food Contamination / Q000032:analysis*; D006108:Graphite; D057230:Limit of Detection; D010087:Oxides
chemical_list: D052157:Aptamers, Nucleotide; D010087:Oxides; D006108:Graphite; D016604:Aflatoxin B1