title: A graphene oxide-based strand displacement amplification platform for ricin detection using aptamer as recognition element.
abstract: The toxic plant protein ricin is a potential agent for criminal or bioterrorist attacks due to the wide availability and relative ease of preparation. Herein, we developed a novel strategy for the detection of ricin B-chain (RTB) based on isothermal strand-displacement polymerase reaction (ISDPR) by using aptamer as a recognition element and graphene oxide (GO) as a low background platform. In this method, ricin-binding aptamer (RBA) hybridized with a short blocker firstly, and then was immobilized on the surface of streptavidin-coated magnetic beads (MBs). The addition of RTB could release the blocker, which could hybridize with the dye-modified hairpin probe and trigger the ISDPR, resulting in high fluorescence intensity. In the absence of RTB, however, the fluorescence of the dye could be quenched strongly by GO, resulting in the extremely low background signal. Thus, RTB could be sensitively detected by the significantly increased fluorescence signal. The linear range of the current analytical system was from 0.75μg/mL to 100μg/mL and the limit of detection (3σ) was 0.6μg/mL. This method has been successfully utilized for the detection of both the RTB and the entire ricin toxin in real samples, and it could be generalized to any kind of target detection based on an appropriate aptamer.
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, 400715 Chongqing, PR China.
authors.forename: Chun Hong
authors.initials: CH
authors.lastname: Li
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, 400715 Chongqing, PR China.
authors.forename: Xue
authors.initials: X
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, 400715 Chongqing, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Tao
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, 400715 Chongqing, PR China.
authors.forename: Dong Mei
authors.initials: DM
authors.lastname: Wang
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, 400715 Chongqing, PR China; College of Pharmaceutical Sciences, Southwest University, 400715 Chongqing, PR China. Electronic address: chengzhi@swu.edu.cn.
authors.forename: Cheng Zhi
authors.initials: CZ
authors.lastname: Huang
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, 400715 Chongqing, PR China. Electronic address: zsj@swu.edu.cn.
authors.forename: Shu Jun
authors.initials: SJ
authors.lastname: Zhen
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D002367:Ricinus communis / Q000737:chemistry; D002619:Chemical Warfare Agents / Q000032:analysis* / Q000493:pharmacokinetics*; D005456:Fluorescent Dyes / Q000737:chemistry; D000067030:Fruit and Vegetable Juices / Q000032:analysis*; D006108:Graphite / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D009693:Nucleic Acid Hybridization / Q000379:methods; D010087:Oxides / Q000737:chemistry; D012276:Ricin / Q000032:analysis* / Q000652:urine*; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D052157:Aptamers, Nucleotide; D002619:Chemical Warfare Agents; D005456:Fluorescent Dyes; D010087:Oxides; D006108:Graphite; D012276:Ricin
keywords: Aptamer; Graphene oxide; Isothermal strand-displacement polymerase reaction; Ricin B-chain