title: A simple, post-additional antioxidant capacity assay using adenosine triphosphate-stabilized 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radical cation in a G-quadruplex DNAzyme catalyzed ABTS-H2O2 system.
abstract: The scavenging of 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radical cation (ABTS(+)) by antioxidants has been widely used in antioxidant capacity assay. Because of ABTS(+) disproportionation, however, this radical cannot be prepared on a large scale and stored long-term, making it unsuitable for high-throughput detection and screening of antioxidants. We developed a modified "post-additional" antioxidant capacity assay. This method possessed two remarkable features: First, instead of natural peroxidases, an artificial enzyme, G-quadruplex DNAzyme, was used for the preparation of ABTS(+), thus greatly reducing the cost of the assay, and eliminating the strict demand for the storage of enzymes. Second, an ABTS(+) stabilizer, adenosine triphosphate (ATP), was used. In the presence of ATP, the disproportionation of ABTS(+) was effectively inhibited, and the lifetime of this radical cation was prolonged about 6-fold (12 days versus 2 days), making the large-scale preparation of ABTS(+) possible. Utilizing this method, the antioxidant capacities of individual antioxidants and real samples can be quantified and compared easily. In addition, this method can be developed as a high-throughput screening method for antioxidants. The screening results could even be judged by the naked eye, eliminating the need for expensive instruments.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, PR China.
authors.forename: Shu-Min
authors.initials: SM
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, PR China.
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, PR China; Key Laboratory of Functional Polymer Materials, Ministry of Education, Nankai University, Tianjin 300071, PR China. Electronic address: kongdem@nankai.edu.cn.
authors.forename: De-Ming
authors.initials: DM
authors.lastname: Kong
authors.affiliation: Key Laboratory of Functional Polymer Materials, Ministry of Education, Nankai University, Tianjin 300071, PR China.
authors.forename: Han-Xi
authors.initials: HX
authors.lastname: Shen
mesh_terms: D000255:Adenosine Triphosphate; D000975:Antioxidants / Q000032:analysis*; D001483:Base Sequence; D052160:Benzothiazoles; D015374:Biosensing Techniques / Q000379:methods*; D002412:Cations; D021881:DNA, Catalytic / Q000737:chemistry; D005609:Free Radicals; D006861:Hydrogen Peroxide; D013053:Spectrophotometry; D013451:Sulfonic Acids
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D002412:Cations; D021881:DNA, Catalytic; D005609:Free Radicals; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide