Automated and ultrasensitive detection of methyl-3-quinoxaline-2-carboxylic acid by using gold nanoparticles probes SIA-rt-PCR

Wei Chen, Yuan Jiang, Baoqing Ji, Changqin Zhu, Liqiang Liu, Chifang Peng, M. Kim Jin, Ruirui Qiao, Zhengyu Jin, Libing Wang, Shuifang Zhu, Chuanlai Xu

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24 Citations (Scopus)


An ultrasensitive and rapid sequential injection analysis (SIA) based on real-time PCR (SIA-rt-PCR) assay was developed by using different nanoparticles for the detection of small molecule chemicals residues. Gold (Au) nanoparticle, conjugated with goat anti-rabbit IgG and duplex strand DNA (dsDNA), was used as a substitute for chemiluminescent probes in an SIA system. By indirect competitive immunoreactions in the SIA system, the gold nanoparticles were attached to antigens which were immobilized by superparamagnetic nanoparticles (SMNPs). The dsDNA on the gold nanoparticles was dehybridized and then the single-stranded DNA (ssDNA) was collected and quantified with rt-PCR, which showed a rather low linearity range from 2.5 atto mol L-1 (aM) to 250 femto mol L-1 (fM) and the LOD was 1.4 aM. This method, which is rapid, automated and capable of high-throughput, was used to detect methyl-3-quinoxaline-2-carboxylic acid (MQCA) residues in real samples. The analytical results had a coefficient of variation of less than 15% and the recovery was 89-108%. Crown

Original languageEnglish
Pages (from-to)2858-2863
Number of pages6
JournalBiosensors and Bioelectronics
Issue number9
Publication statusPublished - 15 May 2009
Externally publishedYes


  • Gold
  • MQCA
  • rt-PCR
  • Sequential injection analysis
  • Superparamagnetic nanoparticles

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