title: Label free electrochemical aptasensor for ultrasensitive detection of ractopamine.
abstract: A label free electrochemical (EC) aptasensor for ultrasensitive detection of ractopamine (RAC) was developed. A special immobilization media consisting of gold nanoparticles/poly dimethyl diallyl ammonium chloride-graphene composite (AuNPs/PDDA-GN) was utilized to improve conductivity and performance of the biosensor. The RAC aptamer was attached on AuNPs of the composite membrane via Au-S bond. The fabrication process of the EC aptasensor was characterized by electrochemical impedance spectroscopy and cyclic voltammetry. The peak currents obtained by differential pulse voltammetry decreased linearly with the increasing of RAC concentrations and the sensor responds approximately logarithmically over a wide dynamic range of RAC concentration from 1.0 × 10(-12)mol/L to 1.0 × 10(-8)mol/L. The linear correlation coefficient of the developed aptasensor was 0.998, the limit of detection was 5.0 × 10(-13)mol/L. The proposed EC aptasensor displayed good stability, reproducibility and robust operation in animal urine. Particularly, the generality of the fabrication approach of electrochemical aptasensor is highlighted with a further example for illegal drugs detection via the aptamer identification.
authors.affiliation: Department of Chemistry, Liaoning Normal University, Dalian 116029, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Yang
authors.affiliation: Institute of Quality Standards and Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: wplcon99@163.com.
authors.forename: Peilong
authors.initials: P
authors.lastname: Wang
authors.affiliation: Institute of Quality Standards and Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Ruiguo
authors.initials: R
authors.lastname: Wang
authors.affiliation: University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Institute of Quality Standards and Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: suxiaoou@caas.cn.
authors.forename: Xiaoou
authors.initials: X
authors.lastname: Su
authors.affiliation: University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: heyujian@gucas.ac.cn.
authors.forename: Yujian
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Chemistry, Liaoning Normal University, Dalian 116029, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.affiliation: Institute of Microbial Biotechnology, Jinan University, Guangzhou 510632, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Yao
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D006133:Growth Substances / Q000652:urine; D053768:Metal Nanoparticles / Q000737:chemistry*; D010627:Phenethylamines / Q000652:urine*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling
chemical_list: D052157:Aptamers, Nucleotide; D006133:Growth Substances; D010627:Phenethylamines; C060897:ractopamine; D006046:Gold
keywords: Aptamer; Cyclic voltammetry; Differential pulse voltammetry; Gold nanoparticles; Graphene; Ractopamine