Low-intensity Magnetic Field Research Articles

Exploring magnetic field treatment into solid-state fermentation of organic waste for improving structural and physiological properties of keratin peptides

This study systematically investigated the effects of a low-intensity magnetic field on the influence of keratinase activity, peptide yield, and structural and functional properties of peptides produced during solid-state fermentation (SSF) of mixed organic substrates (chicken feather powder and okara) using a mutant strain of Bacillus licheniformis. Initially, the magnetic field-assisted SSF (MSSF) conditions were optimized, which provided the optimized conditions as the number of treatments 3 at every 24 h (24, 48, and 72 h) with 4 h holding time at 120 Gs of magnetic intensity (mI). Under the optimum conditions, keratinase activity and peptide production increased by 10.31% and 13.77%, respectively. Further, in order to evaluate the influence of magnetic field treatment on the peptides, MSSF experiments were done under different mI conditions (40, 80, 120, and 160 Gs), followed by the evaluation of the structural changes of the extracted peptides. The structural analysis revealed that mI had a significant impact on the keratin surface. In contrast, secondary structure analysis confirmed the unfolding of the peptide with decreased α-keratin and increased β-keratin, thereby boosting the bioactive properties of the peptides. The highest hydroxyl free radical (.OH), 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging and Fe2+ chelating rates (56.55, 71.36, and 50.72%, respectively) were found at 120 Gs, which were insignificant with the results at 160 Gs. Therefore, MSSF has a positive effect on the proteolysis mechanism, which can increase bioactive peptide production from keratin.

Effect of low-intensity magnetic field on the growth and metabolite of Grifola frondosa in submerged fermentation and its possible mechanisms

This study aimed to investigate the effects of low intensity alternating magnetic field on the submerged fermentation of Grifola frondosa, and its possible mechanism was also explored. Under the optimal shaking flask conditions, amino acids in mycelium with magnetic field treatment significantly increased, and the morphology of mycelium obviously changed. During the scale-up magnetic field-assisted fermentation, Mycelium biomass increased by 12%. The yield of polysaccharides and relative dissolved oxygen in the fermentation broth was higher than in the control group. Transcriptome sequencing results showed that the expression of genes related to amino acid metabolism increased significantly after magnetic treatment. In addition, magnetic field stimulation enhanced the mycelium biomass by upregulation the expression of genes related to cell repair and stress response. This study suggested that applying a magnetic field in submerged fermentation of G frondosa is an innovative approach to produce metabolites.

Magnetospectroscopy of terahertz surface plasmons in subwavelength perforated superlattice thin-films

Surface plasmons, the resonant oscillations of conducting electrons at the interface of negative and positive permittivity materials, pave the way for enhanced electromagnetic wave–matter interactions at a subwavelength scale. On the other hand, spin-dependent magnetotransport ushers an ingenious technology by inculcating electron spin to realize miniaturized, energy-efficient electromagnetic devices. Generally, magneto-resistive devices (viz., multilayer un-patterned magnetic–non-magnetic thin films) relying on magnetotransport mechanisms are not recognized for supporting surface plasmons toward enhanced electromagnetic interactions. However, an amalgamation of surface plasmons with spin-dependent magnetotransport can exploit magnetic (spintronic) degree of freedom in plasmonic devices. In this work, we propose a patterned superlattice (non-magnetic/ferromagnetic thin films) terahertz (THz) magneto-resistive device for supporting surface plasmons toward enhanced electromagnetic interactions. Magnetotransport dependent enhancement and dynamic magnetic modulation of resonant THz transmissions are experimentally demonstrated in subwavelength superlattice (Al/Ni) hole arrays for varying lattice parameters. Our experiments reveal that typical non-magnetic electromagnetic phenomena like surface plasmon resonances can be tweaked by externally applied low intensity magnetic fields [∼few tens of milli-tesla (0–30 mT)]. Experimental outcomes are explicated by spin-dependent terahertz magnetotransport theory in perforated superlattice metal sheets and, therefore, can stimulate a paragon for spin-based integrated photonic technology.

Fabrication of anisotropic collagen-based substrates for potential use in tissue engineering

Stimuli-responsive nanomaterials have the prospective to enable the fabrication of new extracellular matrix-like substrates with unique structures and cell-instructive capabilities. The development of biocompatible collagen substrates with on-demand ordered architectures is an open challenge since it is well-known that the directionality of the collagen fibres affects important cell behaviour, such as proliferation, differentiation, and ultimately, tissue regeneration. Here, an easy and cheap approach to fabricate anisotropic collagen-based substrates exhibiting cells-instructing ability was proposed. Paramagnetic iron oxide nanoparticles (IOPs) coated with polyethylene glycol were synthetized by a coprecipitation and solvothermic method and mixed with a collagen precursors solution. The suspension was then immersed within a static and low-intensity magnetic field to trigger the IOPs self-assembly. Guided by the external stimulus, IOPs assembled along the magnetic field lines into long filamentous structures within the collagen matrix. The solidification of the pre-cursors solution in the presence of filamentous IOPs’ structures promotes the collagen organization into ordered fashions. The obtained collagen substrate demonstrated good cytocompatibility and cells’ instructive properties.

Generation of a rotating high frequency magnetic field designed for use in magnetic hyperthermia

The paper presents two issues: a new method of generating a rotating magnetic field of high frequency and describes the influence of the rotating magnetic field high frequency on energy losses in a magnetic fluid. This new generation method uses a closed magnetic circuit with ferrite elements. It is powered by two high-frequency power amplifiers through transformers with ferrite cores. As a result, it is relatively easy to obtain high amplitude values ​​of the rotating magnetic field intensity. The article describes the results of the operation of rotating magnetic fields in the frequency range from 38 kHz to 370 kHz, with an amplitude of intensity up to 16 kA·m−1 on energy losses in a magnetic fluid. The obtained results indicate that at a constant frequency f the values ​​of the temperature rate increase dT/dt are proportional to the square of intensity of magnetic field ∝H2. Likewise, the values ​​of the rate of temperature increase dT/dt measured with the constant intensity of the rotating magnetic field H are proportional to the square of frequency ∝f2. It was found that in the area of ​​the low magnetic field intensity, energy losses resulting from magnetic relaxation prevail, which decrease with the increase of the field strength H, and then the share of losses due to magnetic hysteresis increases. A comparison of the calorimetric effect in a rotating and alternating magnetic field shows that the rotating field releases 75% more heat energy than the alternating field.

Magneto-inductive open-cell cellular carbon composites with activated carbon as guest phase: Guefoams for energy-efficient VOCs management

Guefoams (guest-containing foams) are a new-class of open-cell cellular materials that extend the properties of conventional foams by incorporating guest phases that convert them into multifunctional materials. This manuscript describes the development of pitch-derived composite guefoams that contain two types of inclusions: iron nanoparticles embedded in the cellular skeleton and activated carbon particles as guest phases. The activated carbon particles significantly increase the specific surface area and gas adsorption capacity. When these materials are exposed to low-intensity magnetic fields, the iron nanoparticles confer a high magneto-inductive capacity that enables ultrafast heating and rapid desorption of adsorbed species. The ability of these materials to act as preconcentrators for volatile organic compounds (VOCs) is demonstrated in this work using toluene as a proof of concept. The Guefoams developed here have greater preconcentration capabilities than current state-of-the-art systems while also being significantly more energy efficient due to the magnetic induction controlled desorption process. This unparalleled blend of properties makes these guefoams a valuable tool for energy-efficient VOCs management.

Comparison of various forces acting on magnetic particles in a low-intensity magnetic field: A 3D FEA

Magnetic agglomeration plays a vital role in enhancing the separation of fine magnetic mineral particles. However, the forces causing magnetic agglomeration in wet low-intensity magnetic separators (LIMS) are poorly understood; this calls for improved understanding of various forces (including magnetic force (Fm), magnetic agglomeration force (Fmm), gravity (G)) acting on magnetic particles in the LIMS. In this study, a 3D low-intensity magnetic field (LIMF) with uniform gradient was simulated, and the different forces acting on magnetic particles were calculated in the form of Fmm/Fm and Fmm/G by finite element analysis (FEA). Results show that magnetic agglomeration force has a significant competitive effect on magnetic separation. However, there are still some methods to weaken the effect of magnetic agglomeration force. This study not only provides theoretical guidance for the innovative development of LIMS, but also opens a new perspective for the recovery of strong magnetic minerals from ore resources.

Low intensity magnetic fields stimulate the electron transport chain in heart mitochondria

Recent studies suggested that low intensity magnetic fields (MF) exerted a stimulatory effect on the mitochondrial metabolic activity, when applied to the whole animals, organs, or single cells. However, the mechanisms and the ranges of MF strength for this stimulation are still unclear. Here we hypothesize that static low intensity MF can regulate mitochondrial electron transport chain activity as such enhance mitochondrial respiration. Nearly uniform low-strength magnetic fields were generated by Helmholtz coils, which were mounted into the water jacket of the measure chamber of an oxygraph.

Neural Circuit Repair by Low-Intensity rTMS.

Electromagnetic brain stimulation is a promising treatment in neurology and psychiatry. However, clinical outcomes are variable and underlying mechanisms remain ill-defined, impeding the development of new effective stimulation protocols. There is increasing application of repetitive transcranial magnetic stimulation (rTMS) to the cerebellum to induce forebrain plasticity through its long-distance cerebello-cerebral circuits. To better understand what magnetic stimulation does within the cerebellum, we have developed tools to generate defined low-intensity (LI) magnetic fields and deliver them in vivo, in 3D organotypic culture and in primary cultures, over a range of stimulation parameters. Here we show that low-intensity rTMS (LI-rTMS) to the cerebellum induces axon growth and synapse formation providing olivocerebellar reinnervation. This repair depends on stimulation pattern, with complex biomimetic patterns being most effective, and this requires the presence of a cellular magnetoreceptor, cryptochrome. To explain these reparative changes, we found that repair-promoting LI-rTMS patterns, but not ineffective ones, increased c-fos expression in Purkinje neurons, consistent with the production of reactive oxygen species by activated cryptochrome. Rather than activating neurons via induced electric currents, we propose that weak magnetic fields act through cryptochrome, activating intracellular signals that induce climbing fibre-Purkinje cell reinnervation. This information opens new routes to optimize cerebellar magnetic stimulation and its potential role as an effective treatment for neurological diseases.

Simulation of magnetoplasmadynamic process with applied magnetic field

The magnetoplasmadynamic thruster is a typical representative of the high-power electric propulsion device, and the magnetoplasmadynamics process is its core operating mechanism. In order to understand the influence of applied magnetic field on its operating characteristics, the particle-in-cell particle simulation method combined with the scale model based on the self-similarity criterion is used to simulate the operating process of magnetoplasmadynamic thruster with applied magnetic field. The reliability of the model and method are verified by comparing with the experimental results. The plasma characteristic parameter distribution of the thruster during ignition is analyzed, and the influence of external magnetic field and cathode current on the thruster performance are discussed. The research results show that the construction of the discharge arc between the cathode and anode is a key step for thruster ignition and efficient operation. A low-intensity magnetic field is not conducive to the construction of a stable discharge arc, while the plasma beam is concentrated near the axis and the main thrust generation mechanism is the self-field acceleration. The discharge arc between cathode and anode is stable by applying a high magnetic field, and the main mechanism of thrust generation is vortex acceleration, which causes the thrust and specific impulse to increase linearly with the strength of the external magnetic field. The efficiency of the thruster increases with cathode current and the applied magnetic field intensity increasing. The discharge voltage increases with the augment of cathode current, but first decreases and then increases with applied magnetic field intensity increasing.

Numerical Model of Eddy Current Inspection with DC Magnetic Field Associated

Most non-destructive techniques can be well represented in a virtual environment, in particular, eddy current testing (ECT) simulation is a useful and well-established tool to predict and represent real inspection situations permitting testing customization in a fast, cheap and efficient way. Conventional ECT generally works with low-intensity magnetic fields, however, for advanced variations of the technique, where external DC magnetic fields can be applied to locally decrease the magnetic permeability, there is no Finite Element Method (FEM) packages available to deal with such nonstandard model. Many authors [1] and [2] have presented this ECT solution for different industrial applications using external DC magnetization to carry nonlinear ferromagnetic materials to the saturation level of the magnetization curve to increase the ECT depth penetration. In general, ECT modelling calculation is benefited by properties of steady-state regime where all magnetic fields are oscillating at the same frequency not permitting through multi-frequency calculation. The present work proposes a simulation solution for such a case where DC magnetic field is associated with ECT. A theoretical model is presented together with experimental results validation.

An extended magnetic-stress coupling model of ferromagnetic materials based on energy conservation law and its application in metal magnetic memory technique

An extended magnetic-stress coupling model based on energy conservation law was established for ferromagnetic materials in low-intensity magnetic fields to develop the metal magnetic memory (MMM) technique, and its application was quantitatively analyzed using the finite element method. Firstly, the verification of the proposed model was given by comparing the influences of stress on relative permeability and residual magnetic field (RMF) signals with experimental data and other theoretical model. Then, the effect of the defect type, size, load magnitude, and lift-off value on the RMF signals was respectively discussed, and their sensitivities on the total characteristic parameter of RMF gradients were compared. In addition, the combined influence of the lift-off value and the defect depth was analyzed. The results indicate that the proposed magneto-stress coupling model is feasible to predict the stress state and structure damage using the MMM technique.

The Impact of Bilayer Rigidity on the Release from Magnetoliposomes Vesicles Controlled by PEMFs.

Stimuli-sensitive nanocarriers have recently been developed as a powerful tool in biomedical applications such as drug delivery, detection, and gene transfer techniques. Among the external triggers investigated, low intensity magnetic fields represent a non-invasive way to remotely control the release of compounds from a magneto-sensitive carrier. Magnetoliposomes (MLs), i.e., liposomes entrapping magnetic nanoparticles (MNPs), are studied due to their capacity to transport hydrophobic and hydrophilic agents, their easy production, and due to the ability of MNPs to respond to a magnetic actuation determining the triggered release of the encapsulated compounds. Here we investigated the design and optimization of the MLs to obtain an efficient on-demand release of the transported compounds, due to the magneto-mechanical actuation induced by applying low-intensity pulsed electromagnetic fields (PEMFs). In particular we studied the effect of the bilayer packing on the ability of MLs, with oleic acid-coated MNPs encapsulated in the bilayer, to respond to PEMFs application. Three kinds of MLs are produced with an increasing rigidity of the bilayer, defined as Liquid Disorder, Liquid Order, and Gel MLs and the delivery of a hydrophilic dye (as a model drug) is investigated. Results demonstrate the efficacy of the magnetic trigger on high-ordered bilayers, which are unable to dampen the perturbation produced by MNPs motion.

Use of Fast Gamma Magnetic Stimulation Over the Left Prefrontal Dorsolateral Cortex for the Treatment of MCI and Mild Alzheimer's Disease: A Double-Blind, Randomized, Sham-Controlled, Pilot Study.

Background: Alzheimer's disease (AD) animal models have shown a reduced gamma power in several brain areas, and induction of these oscillations by non-invasive methods has been shown to modify several pathogenic mechanisms of AD. In humans, the application of low-intensity magnetic fields has shown to be able to produce neural entrainment at the magnetic pulse frequency, making it useful to induce gamma frequencies.Objective: The aim of this study was to assess if the application of fast gamma magnetic stimulation (FGMS) over the left prefrontal dorsolateral cortex would be a safe and well-tolerated intervention that could potentially improve cognitive scores in subjects with mild cognitive impairment and mild AD.Methods: In these randomized, double-blind, sham-controlled study, participants were assigned to either receive daily sessions two times a day of active or sham FGMS for 6 months. Afterward, measurements of adverse effects, cognition, functionality, and depression were taken.Results: Thirty-four patients, 17 in each group, were analyzed for the primary outcome. FGMS was adequately tolerated by most of the subjects. Only four patients from the active FGMS group (23.52%) and one patient from the sham FGMS group (5.88%) presented any kind of adverse effects, showing no significant difference between groups. Nevertheless, FGMS did not significantly change cognitive, functionality, or depressive evaluations.Conclusion: FGMS over the left prefrontal dorsolateral cortex applied twice a day for 6 months resulted to be a viable intervention that can be applied safely directly from home without supervision of a healthcare provider. However, no statistically significant changes in cognitive, functionality, or depression scores compared to sham stimulation were observed.Clinical Trial Registration:www.ClinicalTrials.gov, Identifier: NCT03983655, URL: https://clinicaltrials.gov/ct2/show/NCT03983655.

Change in the cold flowability and wax deposition of crude oil by weak magnetic treatment

The research aims to study how the magnetic fields affect the cold flowability and wax deposition of the crude oil, which has been stirred by the low-intensity magnetic field for a long time. The corresponding cold flowability of crude oil can be improved under a certain level of exposure of magnetic field (60 mT with 600r/min stirring, in a 30 min exposure), which the crude oil tends to behave like Newtonian liquids. The magnetized oil could still maintain the viscosity-reduction effect when the temperature drops to a lower level, the viscosity-reduction rate was more than 10% near the pour point. What lead to the viscosity-reduction effect of magnetized oil is the promotion of the nucleation process of crystal, and subsequently, the obstruction of crystallization. It could be concluded that the weak magnetic treatment could also inhibit wax deposition based on the investigations of the deposition mass under two setups by treating the oil with or without magnetic field. Based on what has been observed in the present study, the wax who adhere to the cold finger tend to be more compact than it used to be after the magnetic treatment.

Extraction and purification of Aspergillus tamarii β-fructofuranosidase with transfructosylating activity using aqueous biphasic systems (PEG/phosphate) and magnetic field

β-fructofuranosidases (FFases) are enzymes involved in sucrose hydrolysis and fructo-oligosaccharides’ production which are of great interest for the food industry. FFase from Aspergillus tamarii URM4634 was extracted using PEG/Phosphate Aqueous Biphasic Systems (ABS), and the impact of magnetic field on the extraction behavior was evaluated. A 24-full experimental design was employed to study the influence of molar mass of PEG, concentrations of PEG and phosphate and pH on the selected response variables, i.e., partition coefficient (K), purification factor (PF), activity yield (Y) and selectivity (S). The influence of magnetic field during partition and NaCl concentration on the same responses was also studied. The best results of FFase extraction without magnetic field (K = 0.50, PF = 4.05, Y = 72.66% and S = 0.06) were observed at pH 8.0 using 12.5% (w/w) PEG 400 and 25% (w/w) NaH2PO4/K2HPO4. Application of the magnetic field allowed improving the performance, with the best results being obtained at the longest distance between magnets (lowest magnetic field) and absence of NaCl (K = 0.93, PF = 4.22, Y = 83.79% and S = 0.09). The outcomes obtained demonstrate that ABS combination with low intensity magnetic field can be used as an efficient FFase pre-purification method.

Reflective fiber-optic magnetic field sensor based on a magnetic-fluid-filled capillary probe structure

A novel reflective magnetic field sensor is presented and experimentally demonstrated. The sensing probe is fabricated by splicing a section of uncoated four-core fiber (FCF) between two sections of no-core fibers (NCFs), and the end face of the last NCF is coated by silver. The sensor structure is sealed in a magnetic fluid (MF)-filled capillary, so that the NCF–FCF–NCF magnetic field sensing probe structure is obtained. The NCF is used to excite the high-order modes of the FCF’s cladding. Combined with the adjustable refractive index of MF, the sensor is sensitive to the magnetic field and temperature. Experimental results indicate that the presented sensor can measure the low magnetic field and high magnetic field. In the low magnetic field ranges of 0–10 mT and 10–18 mT, the wavelength near 1548 nm varies linearly with the magnetic field intensity, and the sensitivities are −7.43 pm mT−1 and −60 pm mT−1, respectively. The sensitivity of the interference intensity is −0.30782 dB mT−1 in the low magnetic field intensity range of 0–18 mT. The sensor under low magnetic field is also affected by temperature. In the temperature range of 20 °C–70 °C, the temperature sensitivity of the wavelength shift around 1548 nm is 62.33 pm °C−1, and the corresponding sensitivities of the interference intensity are −0.03888 dB °C−1 and −0.02076 dB °C−1 in the range of 30 °C–50 °C and 50 °C–70 °C, respectively. However, the effect of temperature on the sensor in the high magnetic field (18–36 mT) can be ignored. Within the high magnetic field intensity range of 26–36 mT, the sensitivity of the interference intensity near 1598 nm is −1.20993 dB mT−1. The dual-parameter matrix is used to eliminate the cross-sensitivity of temperature in the low magnetic field. This sensor, with the advantages of easy fabrication, high sensitivity and low cost, has the potential application in the magnetic field monitoring.

Thermorheological properties of magnetorheological grease and its thermomagnetic coupling mechanism

A heating phenomenon exists in the service process of magneto-rheological devices. For magnetorheological devices using magnetorheological grease (MRG) as the working medium, changes in the medium’s rheological behaviors caused by temperature increase will generate challenges in the reliable service of the devices. With laboratory-prepared MRG as the research object, MRG rheological property laws under different temperatures and magnetic field intensities are investigated, and the magnetic properties of carbonyl iron (CI) powder under different temperatures are analyzed. The relationship between the evolution of the MRG structural system and changes in rheological properties under the action of thermomagnetic coupling is discussed. The results show that the MRG structural system is composed of base carrier liquid soap fibers and magnetic chains under the action of a magnetic field, and the soap fibers can strengthen the structural intensity of the MRG. A decrease in the entanglement degree of the soap fiber structure caused by temperature increase will obviously weaken the intensity of the entire MRG system and narrow the regulation and control scope of the MRG rheological properties. The structural evolution of soap fibers under thermomagnetic coupling will affect the chain formation of magnetic particles and ultimately their rheological properties. At low temperature and magnetic field intensity, the entanglement degree of soap fibers is relatively high, and the magnetic force on magnetic particles is weak, which cannot completely overcome the binding of soap fibers. The influence of soap fibers is the dominant factor affecting the MRG rheological properties. As temperature and magnetic field intensity increase, the entanglement degree of soap fibers decreases, magnetic particles gradually disperse from the soap fibers under the action of a large magnetic field force, and the magnetic chain structure gradually becomes the dominant factor affecting the MRG rheological properties. Moreover, the weakening degree of the temperature increase effect on the MRG rheological properties decreases, and the rheological law changes gradually.

Measuring viscoelastic parameters in Magnetic Resonance Elastography: a comparison at high and low magnetic field intensity

Magnetic Resonance Elastography (MRE) is a non-invasive imaging technique which involves motion-encoding MRI for the estimation of the shear viscoelastic properties of soft tissues through the study of shear wave propagation. The technique has been found informative for disease diagnosis, as well as for monitoring of the effects of therapies. The development of MRE and its validation have been supported by the use of tissue-mimicking phantoms. In this paper we present our new MRE protocol using a low magnetic field tabletop MRI device at 0.5 T and sinusoidal uniaxial excitation in a geometrical focusing condition. Results obtained for gelatin are compared to those previously obtained using high magnetic field MRE at 11.7 T. A multi-frequency investigation is also provided via a comparison of commonly used rheological models: Maxwell, Springpot, Voigt, Zener, Jeffrey, fractional Voigt and fractional Zener. Complex shear modulus values were comparable when processed from images acquired with the tabletop low field scanner and the high field scanner. This study serves as a validation of the presented tabletop MRE protocol and paves the way for MRE experiments on ex-vivo tissue samples in both normal and pathological conditions.

Detection and Aggregation of Listeria Monocytogenes Using Polyclonal Antibody Gold-Coated Magnetic Nanoshells Surface-Enhanced Raman Spectroscopy Substrates

Magnetic nanoshells with tailored surface chemistry can enhance bacterial detection and separation technologies. This work demonstrated a simple technique to detect, capture, and aggregate bacteria with the aid of end-functionalized polyclonal antibody gold-coated magnetic nanoshells (pAb-Lis-AuMNs) as surface-enhanced Raman spectroscopy (SERS) probes. Listeria monocytogenes were used as the pathogenic bacteria and the pAb-Lis-AuMNs, 300 nm diameter, were used as probes allowing facile magnetic separation and aggregation. An optimized covalent bioconjugation procedure between the magnetic nanoshells and the polyclonal antibody was performed at pH six via a carbodiimide crosslinking reaction. Spectroscopic and morphological characterization techniques confirmed the fabrication of stable pAb-Lis-AuMNs. The resulting pAb-Lis-AuMNs acted as a SERS probe for L. monocytogenes based on the targeted capture via surface binding interactions and magnetically induced aggregation. Label-free SERS measurements were recorded for the minimum detectable amount of L. monocytogenes based on the SERS intensity at the 1388 cm−1 Raman shift. L. monocytogenes concentrations exhibited detection limits in the range of 104–107 CFU ml−1, before and after aggregation. By fitting these concentrations, the limit of detection of this method was ∼103 CFU ml−1. Using a low-intensity magnetic field of 35 G, pAb-Lis-AuMNs aggregated L. monocytogenes as demonstrated with microscopy techniques, including SEM and optical microscopy. Overall, this work presents a label-free SERS probe method comprised of a surface-modified polyclonal antibody sub-micron magnetic nanoshell structures with high sensitivity and magnetic induced separation that could lead to the fabrication of multiple single-step sensors.