High sensitivity optochemical and electrochemical metal ion sensor

Micro & nano letters

article

Mohamed Serry¹  Asmaa Gamal²  Mohamed Shaban²  AbdelHameed Sharaf² 

[1] Department of Mechanical Engineering, The American University in Cairo;Yousef Jameel Science and Technology Research Center, The American University in Cairo;NCRRT, Egyptian Atomic Energy Authority

关键词: cadmium;    contact angle;    copper;    electrochemical impedance spectroscopy;    electrochemical sensors;    electrolytes;    gold;    lead;    membranes;    mercury (metal);    nanoparticles;    nanoporous materials;    nickel;    optical sensors;    platinum;    separation;    surface enhanced Raman scattering;    nanosensors;    Cd;    Pb;    Cu;    Co;    Ni;    Hg;    Pt;    Au;    in-situ signal detection device;    heavy metal ions;    nanopores;    porous nanoshells;    liquid electrolyte;    contact angle mismatch;    ion preconcentration;    optical method;    electrochemical separation;    electrochemical impedance spectroscopy;    in-situ surface enhanced Raman scattering;    integrated detection;    metal nanoparticles;    ordered hexagonally packed arrays;    ultrathin porous layer;    coated porous membrane;    aqueous media;    metal ion separation;    metal ion detection;    high sensitivity electrochemical metal ion sensor;    high sensitivity optochemical metal ion sensor;   

DOI  :  10.1049/mnl.2013.0361

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

A novel sensor that deploys opto- and electrochemical techniques for the rapid and highly sensitive separation and detection of metal ions in aqueous media is reported. The sensor comprises a porous membrane coated with an ultra-thin porous layer of highly ordered, hexagonally packed arrays of metal (Au and Pt) nanoparticles with ≤ 25 nm sub-gaps. This platform enables an integrated detection method that relies on in-situ surface enhanced Raman scattering. An additional scheme is utilised based on electrochemical impedance spectroscopy to increase both the selectivity and the sensitivity of the sensor. Electrochemical separation bolsters the effectiveness of the optical method through ion separation and pre-concentration. The latter are induced by forcing the liquid electrolyte through the membrane's nanopores through a new proposed method based on surface tension mismatch. The sensor demonstrates high selectivity for six different heavy metal ions (Hg 2+ , Cd 2+ , Pb 2+ , Cu 2+ , Co 2+ , Ni 2+ ) at concentrations that range from 1 to 20 ppb (1 × 10 −3 –20 × 10 −3 μg/ml). The novelty of this sensor consists of the fact that the separation, pre-concentration and detection of the targeted ions are all performed in a single stage, eliminating the need for time-consuming and complex sample preparation steps.

【 授权许可】

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