title: Nanoporous gold based optical sensor for sub-ppt detection of mercury ions.
abstract: Precisely probing heavy metal ions in water is important for molecular biology, environmental protection, and healthy monitoring. Although many methods have been reported in the past decade, developing a quantitative approach capable of detecting sub-ppt level heavy metal ions with high selectivity is still challenging. Here we report an extremely sensitive and highly selective nanoporous gold/aptamer based surface enhanced resonance Raman scattering (SERRS) sensor. The optical sensor has an unprecedented detection sensitivity of 1 pM (0.2 ppt) for Hg(2+) ions, the most sensitive Hg(2+) optical sensor known so far. The sensor also exhibits excellent selectivity. Dilute Hg(2+) ions can be identified in an aqueous solution containing 12 metal ions as well as in river water and underground water. Moreover, the SERRS sensor can be reused without an obvious loss of the sensitivity and selectivity even after 10 cycles.
authors.affiliation: WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Haixin
authors.initials: H
authors.lastname: Chang
authors.forename: Akihiko
authors.initials: A
authors.lastname: Hirata
authors.forename: Hongkai
authors.initials: H
authors.lastname: Wu
authors.forename: Qi-Kun
authors.initials: QK
authors.lastname: Xue
authors.forename: Mingwei
authors.initials: M
authors.lastname: Chen
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D002232:Carbocyanines / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D058608:Nanopores; D055620:Optical Phenomena; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D052157:Aptamers, Nucleotide; D002232:Carbocyanines; C085321:cyanine dye 5; D006046:Gold; D008628:Mercury