A femtogram level competitive immunoassay of mercury(ii) based on surface-enhanced Raman spectroscopy

Abstract

A femtogram level and specific surface enhanced Raman spectroscopy (SERS) based competitive immunoassay was developed to detect Hg(II) in aqueous solution for the first time. This novel approach provides an alternative, ultrasensitive and specific analytical method for the detection of Hg(II).

An ultrasensitive competitive immunochromatographic assay (ICA) based on surface-enhanced Raman scattering (SERS) for direct detection of 3-amino-5-methylmorpholino-2-oxazolidinone (AMOZ) in tissue and urine samples

“…Many SERS based immunoassays in sandwich format for detecting macromolecules [40][41][42][43], and in competitive format for determination of small molecular compounds [44][45][46] have been reports. In most SERS-based immunoassays, colloidal gold nanoparticles (GNPs) were often used as the substrate for the preparation of immunoprobe because of their easily controllable-size distribution, long-term stability, friendly biocompatibility with antibodies and antigen, and sufficient enhancement of Raman intensity.…”

Liquid magnetic competitive immunoassay of clenbuterol based on surface‐enhanced Raman spectroscopy

“…Soon afterwards, SERS‐based immunoassay has been widely used in qualitative and semiquantitative detections of biomolecules . In general, ‘sandwich’ structures are often constructed in immunoassay for biomacromolecule detections, while for micromolecules, competitive immunoassay is proceeded instead of the former because of the small sizes, lack of enough active recognition and adsorption sites that brought the low efficiency for the formation of immunocomplex …”

“…In our previous studies, a SERS‐based immunoassay approach was developed to detect specific rabbit IgG antigen with the limit of detection (LOD) of 0.1–1 fg ml −1 based on the magnetic core‐shell nanoparticles and ‘sandwich’ structures, and this approach was also employed to perform the bioseparation successfully . However, the ‘sandwich’ structure immunoassay is unsuitable for micromolecule detections due to the small sizes and lack of enough active recognition and adsorption sites . Therefore, the competitive immunoassay has already been employed to detect micromolecules with high specificity based on the different readout approaches.…”

“…Therefore, the competitive immunoassay has already been employed to detect micromolecules with high specificity based on the different readout approaches. For example, trace Hg 2+ ions in aqueous solutions were ultrasensitively detected by SERS‐based competitive immunoassay on a kind of solid biosubstrate with the LOD of about 80 fg ml −1 by our group . Here, clenbuterol (CL) is chosen as a representative of micromolecule for evaluating the competitive immunoassay.…”

Surface plasmon resonance based competitive immunoassay for Cd2+

“…[16][17][18] The members of our research group have also established many methods for detecting metal ions. [19][20][21][22][23][24] Herein, we report a specic and sensitive competitive immunoassay combined SPR for the detection of cadmium (Cd 2+ ) in aqueous solution for the rst time. At present, all antibodies specic for cadmium recognize a chelated form of Cd 2+ , that is, Cd-EDTA.…”