TY - JOUR
T1 - Magnetic Particle Spectroscopy with One-Stage Lock-In Implementation for Magnetic Bioassays with Improved Sensitivities
AU - Chugh, Vinit Kumar
AU - Wu, Kai
AU - Krishna, Venkatramana D.
AU - Di Girolamo, Arturo
AU - Bloom, Robert P.
AU - Wang, Yongqiang Andrew
AU - Saha, Renata
AU - Liang, Shuang
AU - Cheeran, Maxim C.J.
AU - Wang, Jian Ping
N1 - Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/8/12
Y1 - 2021/8/12
N2 - In recent years, magnetic particle spectroscopy (MPS) has become a highly sensitive and versatile sensing technique for quantitative bioassays. It relies on the dynamic magnetic responses of magnetic nanoparticles (MNPs) for the detection of target analytes in the liquid phase. There are many research studies reporting the application of MPS for detecting a variety of analytes including viruses, toxins, nucleic acids, and so forth. Herein, we report a modified version of the MPS platform with the addition of a one-stage lock-in design to remove the feedthrough signals induced by external driving magnetic fields, thus capturing only MNP responses for improved system sensitivity. This one-stage lock-in MPS system is able to detect as low as 781 ng multi-core Nanomag50 iron oxide MNPs (micromod Partikeltechnologie GmbH) and 78 ng single-core SHB30 iron oxide MNPs (Ocean NanoTech). We first demonstrated the performance of this MPS system for bioassay-related applications. Using the SARS-CoV-2 spike protein as a model, we have achieved a detection limit of 125 nM (equal to 5 pmole) for detecting spike protein molecules in the liquid phase. In addition, using a streptavidin-biotin binding system as a proof-of-concept, we show that these single-core SHB30 MNPs can be used for Brownian relaxation-based bioassays while the multi-core Nanomag50 cannot be used. The effects of MNP amount on the concentration-dependent response profiles for detecting streptavidin were also investigated. Results show that by using a lower concentration/amount of MNPs, concentration-response curves shift to a lower concentration/amount of target analytes. This lower concentration-response indicates the possibility of improved bioassay sensitivities by using lower amounts of MNPs.
AB - In recent years, magnetic particle spectroscopy (MPS) has become a highly sensitive and versatile sensing technique for quantitative bioassays. It relies on the dynamic magnetic responses of magnetic nanoparticles (MNPs) for the detection of target analytes in the liquid phase. There are many research studies reporting the application of MPS for detecting a variety of analytes including viruses, toxins, nucleic acids, and so forth. Herein, we report a modified version of the MPS platform with the addition of a one-stage lock-in design to remove the feedthrough signals induced by external driving magnetic fields, thus capturing only MNP responses for improved system sensitivity. This one-stage lock-in MPS system is able to detect as low as 781 ng multi-core Nanomag50 iron oxide MNPs (micromod Partikeltechnologie GmbH) and 78 ng single-core SHB30 iron oxide MNPs (Ocean NanoTech). We first demonstrated the performance of this MPS system for bioassay-related applications. Using the SARS-CoV-2 spike protein as a model, we have achieved a detection limit of 125 nM (equal to 5 pmole) for detecting spike protein molecules in the liquid phase. In addition, using a streptavidin-biotin binding system as a proof-of-concept, we show that these single-core SHB30 MNPs can be used for Brownian relaxation-based bioassays while the multi-core Nanomag50 cannot be used. The effects of MNP amount on the concentration-dependent response profiles for detecting streptavidin were also investigated. Results show that by using a lower concentration/amount of MNPs, concentration-response curves shift to a lower concentration/amount of target analytes. This lower concentration-response indicates the possibility of improved bioassay sensitivities by using lower amounts of MNPs.
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U2 - 10.1021/acs.jpcc.1c05126
DO - 10.1021/acs.jpcc.1c05126
M3 - Article
C2 - 36199678
AN - SCOPUS:85113676539
SN - 1932-7447
VL - 125
SP - 17221
EP - 17231
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 31
ER -