Improved electrochemical performances of polyaniline nanotubes-poly-L-lysine composite for label-free impedance detection of DNA hybridization  

作　　者：YANG Tao,JIANG Chen,ZHANG Wei & JIAO Kui Key Laboratory of Eco-chemical Engineering,Ministry of Education College of Chemistry and Molecular Engineering,Qingdao University of Science and Technology,Qingdao 266042,China 

出　　处：《Science China Chemistry》2010年第6期1371-1377,共7页中国科学（化学英文版）

基　　金：the support from the National Natural Science Foundation of China (20635020 , 20805025 & 20975057);Doctoral Foundation of the Ministry of Education of China (20060426001) ;Natural Science Foundation of Qingdao City (09-1-3-25-jch)

摘　　要：A sensitive label-free DNA hybridization biosensing platform was fabricated based on the synergistic effect of polyaniline nanotubes (PANInt) and poly-L-lysine (pLys).The composite of pLys and PANInt was coated onto the carbon paste electrode (CPE) to form a uniform and very stable nanocomposite membrane.The pLys in the composite film not only acts as a membrane to retain good electron transfer capability of PANInt even at physiological pH,but also possesses fine biocompatibility for bio-analytes.DNA probes with negatively charged phosphate groups were readily linked to the positively charged pLys surface due to the strong electrostatic affinity.The synergistic effect of PANInt and pLys could significantly enhance the sensitivity of DNA hybridization recognition.The phosphinothricin acetyltransferase (PAT) gene fragment from transgenic corn and the polymerase chain reaction amplification of the terminator of nopaline synthase gene from the real sample of a kind of transgenic soybean were detected by this DNA electrochemical biosensor via label-free impedance method.This stable composite gives convenient permselectivity properties as a transducer material for the design of modern electrochemical impedance biosensor using [Fe(CN)6]3-/4as an indicator.A sensitive label-free DNA hybridization biosensing platform was fabricated based on the synergistic effect of polyaniline nanotubes (PANInt) and poly-L-lysine (pLys).The composite of pLys and PANInt was coated onto the carbon paste electrode (CPE) to form a uniform and very stable nanocomposite membrane.The pLys in the composite film not only acts as a membrane to retain good electron transfer capability of PANInt even at physiological pH,but also possesses fine biocompatibility for bio-analytes.DNA probes with negatively charged phosphate groups were readily linked to the positively charged pLys surface due to the strong electrostatic affinity.The synergistic effect of PANInt and pLys could significantly enhance the sensitivity of DNA hybridization recognition.The phosphinothricin acetyltransferase (PAT) gene fragment from transgenic corn and the polymerase chain reaction amplification of the terminator of nopaline synthase gene from the real sample of a kind of transgenic soybean were detected by this DNA electrochemical biosensor via label-free impedance method.This stable composite gives convenient permselectivity properties as a transducer material for the design of modern electrochemical impedance biosensor using [Fe(CN)6]3-/4as an indicator.

关 键 词：POLY-L-LYSINE POLYANILINE NANOTUBES DNA electrochemical biosensor PAT GENE NOS GENE 

分 类 号：Q503[生物学—生物化学]