An amplified surface plasmon resonance "turn-on" sensor for mercury ion using gold nanoparticles

Chia Chen Chang, Shenhsiung Lin, Shih Chung Wei, Chen Yu Chen, Chii Wann Lin*

*Corresponding author for this work

Research output: Contribution to journalJournal Article peer-review

60 Scopus citations


Inorganic mercury ion (Hg 2+) has been shown to coordinate to DNA duplexes that feature thymine-thymine (T-T) base pair mismatches. This observation suggests that an Hg 2+-induced conformational change in a single-stranded DNA molecule can be used to detect aqueous Hg 2+. Here, we have developed an analytical method using surface plasmon resonance (SPR) to develop a highly selective and sensitive detection technique for Hg 2+ that takes advantage of T-Hg 2+-T coordination chemistry. The general concept used in this approach is that the " turn-on" reaction of a hairpin probe via coordination of Hg 2+ by the T-T base pair results in a substantial increase in the SPR response, followed by specific hybridization with a gold nanoparticle probe to amplify the sensor performance. Meanwhile, the limit of detection is 1nM, which is lower than other recently developed techniques. A linear correlation is observed between the measured SPR reflectivity and the logarithm of the Hg 2+ concentration over the concentration range of 5-5000nM. Additionally, the SPR system provides high selectivity for Hg 2+ in the presence of other divalent metal ions up to micromolar concentration levels. The proposed approach is also successfully utilized for the determination of Hg 2+ in water samples.

Original languageEnglish
Pages (from-to)235-240
Number of pages6
JournalBiosensors and Bioelectronics
Issue number1
StatePublished - 15 12 2011
Externally publishedYes


  • Hairpin probe
  • Mercury ion
  • Surface plasmon resonance
  • Thymine-thymine mismatch
  • Turn-on detection


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