Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (24): 2507-2512.DOI: 10.6023/A12100740 Previous Articles     Next Articles



邓洪平a, 王国建b, 朱邦尚a, 朱利娟b, 王大力b, 庄园园b, 朱新远a,b   

  1. a 分析测试中心 上海交通大学 上海 200240;
    b 化学化工学院 上海交通大学 上海 200240
  • 投稿日期:2012-10-05 发布日期:2012-12-06
  • 通讯作者: 朱新远;
  • 基金资助:
    项目受国家重点基础研究计划(Nos. 2012CB821500, 2013CB834506)、国家自然科学基金(No. 20974062)、上海市启明星计划(No. 11QH1401500)和国家杰出青年科学基金(No. 21025417)资助.

Label-Free DNA Detection through Energy Transfer of Conjugated Polymer Complexes

Deng Hongpinga, Wang Guojianb, Zhu Bangshanga, Zhu Lijuanb, Wang Dalib, Zhuang Yuanyuanb, Zhu Xinyuana,b   

  1. a Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai 200240, China;
    b School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
  • Received:2012-10-05 Published:2012-12-06
  • Supported by:
    Project supported by the National Basic Research Program (Nos. 2012CB821500, 2013CB834506), the National Natural Science Foundation of China (No. 20974062), Shanghai Rising-Star Program (No. 11QH1401500) and China National Funds for Distinguished Young Scientists (No. 21025417).

Label-free DNA detection is a highly sensitive and selective method with great scientific and social significance. Water-soluble cationic conjugated polymer (CCP), poly(9,9-bis(6'-N,N,N-trimethylammonium)-hexyl)-fluorene phenylene) (PFP), was synthesized by cross coupling reaction under the catalysis of palladium, and water-soluble anionic conjugated polymer (ACP), poly(3-thiophene sodium acetate) (P3TSA), was prepared through oxidative addition polymerization with anhydrous ferric chloride as the catalyst. Both PFP and P3TSA were well characterized by 1H nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) tests. Owing to the existence of opposite ionic side-chains, PFP and P3TSA were both water-soluble and could form polymer complexes through electrostatic interactions. The transmittance measurements of the polymer complex solution with wavelength ranging from 600 to 750 nm were performed. The results showed that the transmittance was almost unchanged for all samples, confirming the high solubility and stability of polymer complexes. The ultraviolet-visible (UV-vis) and photoluminescence emission measurements showed that the emission spectrum of PFP overlapped a lot with the absorption spectrum of P3TSA, proving the energy transfer from PFP (donor) to P3TSA (acceptor). By fixing the donor concentration, energy transfer efficiency (ETEF) of the polymer complexes increased with the concentration of P3TSA. With the enhancement of P3TSA concentration, the ETEF increased slowly at first and then relatively fast at a high P3TSA concentration. A sample with a high ETEF was selected to investigate the effect of DNA probe (X1) concentration on ETEF. It was observed that ETEF decreased with the increase of X1 concentration, owing to the repulsion of P3TSA by negative charged DNA probes. DNA hybridization was conducted by using 0.2 nmol of X1 as a probe. The experimental results showed that the perfectly matched, double mismatched and non-matched target DNA could be well distinguished with obvious photoluminescence signals. In conclusion, a new label-free DNA detection method with high selectivity has been successfully developed based on the energy transfer of conjugated polymer complexes.

Key words: conjugated polymer, DNA detection, label-free, polymer complexes, energy transfer