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Here we report a novel ultrasensitive surface-enhanced Raman scattering (SERS) immunosensor based on the flower-like gold nanoparticles (AuNFs) and magnetic bead separation for homogeneous detection of amantadine (AMD) in chicken just by one-step. The 5, 5′-dithiobis (2-nitrobenzoicacid) (DTNB) modified AuNFs and N-(1-adamantyl) ethylenediamine (AEDA) conjugated denatured BSA (AEDA-dBSA) was used as the SERS nanoprobe. And the capture probe was anti-AMD monoclonal antibody (mAbs)-functionalized magnetic beads (MNBs-mAbs). An immunoreaction occurred between free AMD and SERS nanoprobe for competing limited binding sites of MNBs-mAbs. This work combined inherent sensitive property of SERS with antibody-antigen highly specificity recognition for the AMD detection. The analytical results showed that the SERS-based immunosensor was sensitive, simple and reliable with a limit of detection (LOD) of 0.005 ng/mL for AMD, which were 2 orders of magnitude better than an enzyme-linked immunosorbent assay based on the same immunoreagents. Analysis of AMD-spiked chicken samples revealed that the developed immunosensor provided accepted recoveries ranging from 74.76%-89.34% with coefficient of variation less than 15.04%. This strategy represents a simple, reliable, and universal approach for detection of chemical contaminants in food samples. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, denatured bovine serum albumin (dBSA) has been developed as a useful scaffold for appending multiple oligonucleotides (ODNs), and the resulted novel dBSA-ODNs covalent hybrid can be self-assembled to the surface of CdTe quantum dots (QDs) via complexation with unoccupied coordination metal sites on QDs'' surface. The formed QDs/dBSA-ODNs bioconjugate could keep a long-term stability in aqueous solution while maintaining its fluorescence quantum yield and spectral properties. Furthermore, the QDs/dBSA-ODNs also can be readily hybridized with an anti-rHuEPO-α aptamers linked AuNPs (Apt-AuNPs) to form a fluorescent resonance energy transfer-based nano-biosensing system for highly sensitive and selective detection of rHuEPO-α protein lowered to 53.6pM in a rapid, simple manner. [Copyright &y& Elsevier]