Magnetic Nanoparticle Enhanced Surface Plasmon Resonance Sensing and Its Application for the Ultrasensitive Detection of Magnetic Nanoparticle-Enriched Small Molecules

Abstract

Magnetic nanoparticles (MNPs) have been frequently used in bioseparation, but their applicability in bioassays is limited due to their extremely small size so that sensitive detection is difficult to achieve using a general technique. Here, we present an amplification technique using MNPs for an enhanced surface plasmon resonance (SPR) bioassay. The amplification effect of carboxyl group modified Fe(3)O(4) MNPs of two sizes on SPR spectroscopy is first demonstrated by assembling MNPs on amino group modified SPR gold substrate. To further evaluate the feasibility of the use of Fe(3)O(4) MNPs in enhancing a SPR bioassay, a novel SPR sensor based on an indirect competitive inhibition assay (ICIA) is developed for detecting adenosine by employing Fe(3)O(4) MNP-antiadenosine aptamer conjugates as the amplification reagent. The results confirm that Fe(3)O(4) MNPs can be used as a powerful amplification agent to provide a sensitive approach to detect adenosine by SPR within the range of 10-10,000 nM, which is much superior to the detection result obtained by a general SPR sensor. Importantly, the present detection methodology could be easily extended to detect other biomolecules of interest by changing the corresponding aptamer in Fe(3)O(4) MNP-aptamer conjugates. This novel technique not only explores the possibility of the use of SPR spectroscopy in a highly sensitive detection of an MNP-based separation product but also offers a new direction in the use of Fe(3)O(4) MNPs as an amplification agent to design high performance SPR biosensors.

Multiplexed magnetic nanoparticle-antibody conjugates (MNPs-ABS) based prognostic detection of ovarian cancer biomarkers, CA-125, β-2M and ApoA1 using fluorescence spectroscopy with comparison of surface plasmon resonance (SPR) analysis

“…S6 exhibits a typical Fe-O-Fe absorption bands of HOOC-MNP at 548 cm À 1 , and the C ¼O and O-H stretches of the COOH at $1710 cm À 1 and $ 3500 cm À 1 (Wang et al, 2010), which indicates the Carboxylic acid group was chemical bound on the surface of the Fe 3 O 4 MNP. Comparing with the FT-IR spectra of carboxyl-Fe 3 O 4 MNP, the characteristic peaks of N-H of the CONH at 3100-3600 cm À 1 were observed in the FT-IR spectrum of MNPAb.…”

Recent advances in biological detection with magnetic nanoparticles as a useful tool

“…Wang et al [117] developed a novel SPR sensor based on an indirect competitive inhibition assay (ICIA) for the detection of adenosine by employing Fe 3 O 4 MNPs-anti adenosine aptamer conjugates as the amplification reagent. Their results demonstrated that Fe 3 O 4 MNPs can be utilized as a powerful amplification agent to provide a sensitive way of detecting adenosine via SPR within the range of 10-10000 nmol/L, which is much lower than the detection results of a general SPR sensor.…”

Blu-ray based optomagnetic aptasensor for detection of small molecules

“…MNP-based detection of biomolecules has been applied to both surface-based (Bruls et al 2009;Mani et al 2009;Nash et al 2012;Tekin et al 2013;Wang et al 2010;Wang and Gan 2009) and volume-based assays (Aurich et al 2006;Bamrungsap et al 2011;Chun et al 2011;Göransson et al 2010;Josephson et al 2001;Liang et al 2011;Liong et al 2013;Ranzoni et al 2012;Sun et al 2006;Zhang et al 2013a). The latter typically employs sandwich binding-induced clustering where a molecule of interest is bound to multiple receptors tethered onto MNP surfaces, resulting in the agglutination of MNPs.…”