Insulator‐based dielectrophoresis combined with the isomotive AC electric field and applied to single cell analysis

We developed an insulator‐based dielectrophoretic (iDEP) creek‐gap device that enables the isomotive movement of cells and that is suitable for determining their DEP properties. In the iDEP creek‐gap device, a pair of planar insulators forming a single fan‐shaped channel allows the induction of the isomotive iDEP force on cells. Hence, the cells’ behavior is characterized by straight motion at constant velocity in the longitudinal direction of the channel. Operation of the device was demonstrated using human breast epithelial cells (MCF10A) by applying an AC voltage of V_pp = 34 V peak‐to‐peak and frequencies of 200 kHz and 50 MHz to the device. Subsequently, the magnitude of DEP forces and the real part of the ClausiusMossotti (CM) factor, Re(β), were deduced from the measured cell velocity. The values of Re(β) were 0.14 ± 0.01 for the frequency of 200 kHz and ?0.12 ± 0.01 for 50 MHz. These results demonstrated that the DEP properties of the cells could be extracted over a wide field frequency range. Therefore, the proposed iDEP creek‐gap device was found to be applicable to cell analysis.     

Examination of the dielectrophoretic spectra of MCF7 breast cancer cells and leukocytes

The detection of circulating tumor cells (CTCs) in blood is crucial to assess metastatic progression and to guide therapy. Dielectrophoresis (DEP) is a powerful cell surface marker-free method that allows intrinsic dielectric properties of suspended cells to be exploited for CTC enrichment/isolation from blood. Design of a successful DEP-based CTC enrichment/isolation system requires that the DEP response of the targeted particles should accurately be known. This paper presents a DEP spectrum method to investigate the DEP spectra of cells without directly analyzing their membrane and cytoplasmic properties in contrast to the methods in literature, which employ theoretical assumptions and complex modeling. Integrating electric field simulations based on DEP theory with the experimental data enables determination of the DEP spectra of leukocyte subpopulations, polymorphonuclear and mononuclear leukocytes, and MCF7 breast cancer cells as a model of CTC due to their metastatic origin over the frequency range 100 kHz–50 MHz at 10 V_pp. In agreement with earlier findings, differential DEP responses were detected for mononuclear and polymorphonuclear leukocytes due to the richness of the cell surface features and morphologies of the different leukocyte types. The data reveal that the strength of the DEP force exerted on MCF7 cells was particularly high between 850 kHz and 20 MHz. These results illustrate that the proposed technique has the potential to provide a generic platform to identify DEP responses of different biological particles.     

Combined detection of AC‐electrokinetic effects: Experiments with three‐axial chicken red blood cells

Dielectrophoresis (DEP), electrorotation (ROT), and electro‐orientation were used for the dielectric spectroscopy of nucleated three‐axial chicken red blood cells (CRBCs). Because the different AC‐electrokinetic effects are not mutually independent, their DEP and ROT spectra were combined in ranges separated by the reorientation of the CRBCs in the inhomogeneous linear DEP and circular ROT fields. This behavior can be qualitatively described by a single‐shell ellipsoidal model. Whereas in linear fields, the maximum of the Clausius–Mossotti factor along the three axes determines the orientated axis, in circular fields, the minimum of the factor determines the axis perpendicularly orientated to the field plane. Quantitatively, it has not been possible to find a consistent parameter set for fitting the DEP and ROT spectra, as well as the reorientation frequencies. Our ellipsoidal CRBC standard model had semiaxes of a = 7.7 μm, b = 4.0 μm, and c = 1.85 μm, a relative permittivity of 35 to 45 and conductivity of 0.36 to 0.04 S/m for the cytoplasm, combined with a specific capacitance of 10 to 14 mF/m² and a conductivity of 3500 S/m² for the cell membrane. The fits in different external conductivity ranges between external conductivities of 0.015 and 1.0 S/m were improved when the membrane capacitance was changed between 4 to 25 mF/m² depending on the method used. A similar transition was reflected in the effective properties of a three‐shell spherical model containing an internal membranous sphere with the geometry of the CRBC nucleus. Our findings suggest that the simultaneous interpretation of various AC‐electrokinetic spectra is a step toward the dielectric fingerprinting of biological cells.     

Synthesis of chalcone‐containing methacrylate‐based hydrogen bonded side chain liquid crystalline polymer and its dielectric properties

In this work, a new methacrylate‐based hydrogen bonded side chain liquid crystalline polymer having chalcone moieties (HBCP) was prepared from poly(4‐(3‐(pyridin‐4‐yl)acryloyl) phenyl methacrylate) and 11‐(4‐cyanobiphenyl‐4(‐oxy) undekan‐1‐ol (LC11)) by molecular self‐assembly processes via hydrogen bond formation between nitrogen of the HBCP and hydroxyl group of the LC11. The formation of H bond was confirmed by using Fourier transform infrared (FTIR) spectroscopy. The phase transition temperatures and liquid crystalline phases of the HBCP were examined by DSC and POM measurements. The dielectric properties of HBCP have been determined by impedance analyzer within the frequency interval of 100 Hz–15 MHz. According to Cole–Cole plot, the equivalent circuit of the LC system has been found as a capacitor in parallel with a resistor. The resonance frequency, f_r, of the R–C circuit has also been calculated as 1.59 MHz by phase angle versus frequency curve. The dielectric relaxation type of HBCP has been determined as nearly‐Debye type because the absorption coefficient, α, equals to 0.01655. From the conductivity point of view, HBCP displays dc conductivity at the low and high frequency regions that correspond to 100 Hz–12 kHz and 3.3 MHz–15 MHz, respectively. On the other hand, it has been revealed that the ac conductivity of the LC system investigated obeys Super Linear Power Law (SLPL) at the intermediate frequency domain. Copyright © 2015 John Wiley & Sons, Ltd.     

Dielectrophoretic deformation of breast cancer cells for lab on a chip applications

This paper presents the development and experimental analysis of a curved microelectrode platform for the DEP deformation of breast cancer cells (MDA‐MB‐231). The platform is composed of arrays of curved DEP microelectrodes which are patterned onto a glass slide and samples containing MDA‐MB‐231 cells are pipetted onto the platform's surface. Finite element method is utilised to characterise the electric field gradient and DEP field. The performance of the system is assessed with MDA‐MB‐231 cells in a low conductivity 1% DMEM suspending medium. We applied sinusoidal wave AC potential at peak to peak voltages of 2, 5, and 10 V_pp at both 10 kHz and 50 MHz. We observed cell blebbing and cell shrinkage and analyzed the percentage of shrinkage of the cells. The experiments demonstrated higher percentage of cell shrinkage when cells are exposed to higher frequency and peak to peak voltage electric field.     

Dielectric relaxation and conductivity studies on (PEO:LiClO4) polymer electrolyte with added ionic liquid [BMIM][PF6]: Evidence of ion–ion interaction

Polymer electrolytes, (PEO:LiClO₄)+x IL (1‐Buty‐3‐methylimidazolium hexafluorophosphate) with varying concentration of IL; x = 0,5,10,15,20 wt % have been prepared by solution cast technique and characterized by X‐Ray diffraction, differential scanning calorimetery, FTIR, conductivity and dielectric relaxation measurements in the frequency range of 100 Hz–5 MHz. Temperature dependence of relaxation frequency and conductivity were found to be typical of thermally activated process both at T > T_m and T < T_m. Composition dependence of conductivity, dielectric relaxation, and degree of crystallinity has also been studied. On addition of IL, the degree of crystallinity after a decrease at 5 wt % IL increases slightly at 10 wt % and then finally decreasing. Variation of conductivity and relaxation frequency with composition could only be partly explained on the basis of variation of degree of crystallinity. An additional feature of ion–ion interaction (contact ion pair formation between IL or salt cations and their associated anions) has been invoked which was supported by FTIR studies. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011     

Dielectrophoresis microbial characterization and isolation of Staphylococcus aureus based on optimum crossover frequency

Characterization of antibiotic-resistant bacteria is a significant concern that persists for the rapid classification and analysis of the bacteria. A technology that utilizes the manipulation of antibiotic-resistant bacteria is key to solving the significant threat of these pathogenic bacteria by rapid characterization profile. Dielectrophoresis (DEP) can differentiate between antibiotic-resistant and susceptible bacteria based on their physical structure and polarization properties. In this work, the DEP response of two Gram-positive bacteria, namely, Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-susceptible S. aureus (MSSA), was investigated and simulated. The DEP characterization was experimentally observed on the bacteria influenced by oxacillin and vancomycin antibiotics. MSSA control without antibiotics has crossover frequencies ($f_{x0}$) from 6 to 8 MHz, whereas MRSA control is from 2 to 3 MHz. The $f_{x0}$ changed when bacteria were exposed to the antibiotic. As for MSSA, the $f_{x0}$ decreased to 3.35 MHz compared to $f_{x0}$ MSSA control without antibiotics, MRSA, $f_{x0}$ increased to 7 MHz when compared to MRSA control. The changes in the DEP response of MSSA and MRSA with and without antibiotics were theoretically proven using MyDEP and COMSOL simulation and experimentally based on the modification to the bacteria cell walls. Thus, the DEP response can be employed as a label-free detectable method to sense and differentiate between resistant and susceptible strains with different antibiotic profiles. The developed method can be implemented on a single platform to analyze and identify bacteria for rapid, scalable, and accurate characterization.     

Identification of relaxation processes in pure polyethylene oxide (PEO) films by the dielectric permittivity and electric modulus formalisms

The ac‐impedance of bulk‐like films of pure polyethylene oxide (PEO) polymer was measured as a function of frequency f in the range 0.1 to 10⁷ Hz at various constant temperatures T (155 − 330 K ). The as‐measured data were analyzed by electric permittivity and modulus formalisms to unveil which dielectric and conductive relaxation processes were responsible for their relaxation behavior below/above glass transition temperature T_g of pure PEO polymer. At T > T_g , none of the α ‐, β ‐, or γ ‐relaxations could be inferred for studied pure PEO films from frequency variation of measured imaginary part ε′′(f, T) of complex dielectric permittivity , as low‐frequency losses masked real dielectric contribution to the measured ε′′(f, T) at low frequencies and high temperatures. However, at T < T_g , a broad, relaxation process has been observed in the high‐frequency part of their isothermal ε′′(f, T) − f spectra, which can be related to the β ‐ or γ ‐dielectric relaxation process. Nonlinear regressions of the measured ε′′(f, T) − f data for T < T_g yielded moral fits to a simple addition of a Havriliak‐Negami function, and a Bergman‐loss Kohlrausch‐Williams‐Watts‐type function, with the relaxation time τ_max(T) obtained from Havriliak‐Negami‐fitting parameters, was found to follow a thermally activated Arrhenius‐like relaxation behavior. Conversely, representation of the imaginary part M′′(f, T > T_g) − f spectra of complex electric modulus was found to depict 2 overlapped relaxation processes, which were detached well by a nonlinear regression of a simple superposition of 2 different M′′(f)  expressions having the form of the universal Bergman loss function, where it was found that the relaxation time is also thermally activated.     

Dielectric properties of tetragonal tungsten bronze films deposited by RF magnetron sputtering

Tetragonal tungsten bronze (TTB) films have been synthesised on Pt(111)/TiO₂/SiO₂/Si substrates from Ba₂LnFeNb₄O₁₅ ceramics (Ln = La, Nd, Eu) by RF magnetron sputtering. X-ray diffraction measurements evidenced the multi-oriented nature of films with some degrees of preferential orientation along (111). The dependence of the dielectric properties on temperature and frequency has been investigated. The dielectric properties of the films are similar to those of the bulk, i.e., ε ∼150 and σ ∼10⁻⁶ Ω⁻¹ cm⁻¹ at 1 MHz and room temperature. The films exhibit two dielectric anomalies which are attributed to Maxwell Wagner polarization mechanism and relaxor behaviour. Both anomalies are sensitive to post-annealing under oxygen atmosphere and their activation energies are similar E_a ∼0.30 eV. They are explained in terms of electrically heterogeneous contributions in the films.     

Dielectric spectroscopy of nanocomposites based on iPP and aPS treated in the water solutions of alkali metal salts

In this paper, a new simple and environmentally friendly treatment technique for obtaining polymer nanocomposites with appropriate dielectric properties has been presented. Sheets of isotactic polypropylene and atactic polystyrene were immersed in 3 saturated water solutions of alkali metal salts (LiCl, NaCl, and KCl) at 2 fixed temperatures (23°C and 90°C), and 3 DC electrical potentials (+4 kV, −4 kV, and ground potential) were applied. A quantification of alkali metals in the polymer sheets was conducted by inductively coupled plasma optic emission spectrometry. The obtained concentration values were from 7.38·10⁻⁹ mol/cm³ to 1.25·10⁻⁷ mol/cm³. The qualitative analysis of potassium distribution in the polymer matrix was conducted by time‐of‐flight secondary ion mass spectrometry cross‐sectional record. The relative dielectric constant (ε′) of samples was investigated in the frequency range from 20 Hz to 9 MHz at the constant temperature of 22°C. Stable values of ε′ in fully measured frequency range were observed for both pure and treated samples. Next, the results of the dielectric spectroscopy measurements were compared and established the kind of treatment that provided the highest value of ε′. The relationship between the concentrations of alkali metals and the values of relative dielectric constant was determined for the samples obtained by a treatment at 90°C and +4 kV.     

Effect of arrangement of nano and micro barium titanate (BaTiO3) particles on the enhanced dielectric constant of high‐density polyethylene (HDPE)/BaTiO3

The aim of this study is to improve the dielectric and mechanical properties of HDPE/BaTiO₃ composites by binary BaTiO₃ particles, when the volume fraction of BaTiO₃ is constant. In this study, it was found that the pack density of binary BaTiO₃ particles in HDPE/BaTiO₃ composite relies on particle ratio and volume fraction of small particles. It is found that the addition of 50 vol % 1600 nm BaTiO₃ particles can boost the dielectric constant of HDPE control from 2 to 30 (14 times higher) at 40 Hz and 19 (8.5 times higher) at 40 MHz, respectively. When the particle ratio was 4, the substitution of 10 vol % 1600 nm BaTiO₃ particles by 10 vol % 400 nm BaTiO₃ particles can further enhance the dielectric constant of HDPE/L‐BT (10/10) from 30 to 50 (67% increase) at 40 Hz and from 19 to 42 (121% increase) at 40 MHz, respectively, without greatly influencing the volume resistivity of HDPE composites. In addition, the thermal conductivity of HDPE with binary BaTiO₃ particles were all above 2.0 W/(m•K). © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1101–1108     

A Cole‐Cole Dielectric Relaxation Analysis of Albumin and γ‐Globulins for Protein Quantification by Electrical Impedance Spectroscopy

Optimal serum protein concentrations are vital for normal body functioning. Affordable while accurate protein quantification methods with minimum processing requirements are needed for diagnosis of related diseases. The standard automated chemistry analyzer is limited by high installation and maintenance costs. This study proposes the use of electrical impedimetric spectroscopy (EIS) as an alternative to current methods. Its practical applicability was tested using albumin and γ‐globulin or their miscellanea in three different media; water, serum and tissue‐mimicking phantoms at 25 °C. Impedance measurements were taken between frequency f=0.10 MHz to 300 MHz by an impedance analyzer. A Cole‐Cole analysis was used to elucidate the stepwise variations in the dielectric parameters of the protein medium so as to obtain empirical dielectric parameter‐protein concentration relationships and their correlation coefficients R². From the results, linear relationships between parameters and protein concentrations with high correlation coefficients over R²=0.90 were observed. Resistance to charge transfer R_ct and characteristic frequency f_c were significantly altered by changing protein concentrations as compared to bulk solution resistance R_s, relaxation time constant τ and shape factor α. The relationships developed would aid in monitoring changes in body fluid protein concentrations by EIS.     

Gelation Studies on a Radical Chain Cross‐Linking Copolymerization Process: Comparison of the Critical Exponents Obtained by Dynamic Light Scattering and Rheology

Summary: The sol–gel transition of a radical chain cross‐linking copolymerization system [N‐vinylcaprolactam/2‐hydroxylethyl methacrylate/allyl methacrylate] has been studied using in situ time‐resolved dynamic light scattering (DLS) and in situ rheology. A critical dynamic behavior was observed near the sol–gel transition, which was characterized by the presence of a power‐law spectra over three decades in the time–intensity correlation function g₂(t) − 1 ∼ t^−μ and over two decades in the oscillatory shear experiment G′(ω) ∼ G″(ω) ∼ ωⁿ. A comparison of the obtained critical exponents μ ≈ 0.62 and n ≈ 0.75 was made. The theory predicts a relationship between these exponents, but up to now no experimental comparison has been done. The experimental results favor the percolation model, with a fractal dimension d_f of the gel clusters of 1.67.

Double‐logarithmic plot of time–intensity correlation functions g₂(t) − 1 versus the delay time t.     

Structural characterization and dielectric properties of the solid solutions AgPb(Sb,Bi)S3

The new solid solutions AgPbSb_1 − x Bi _x S₃ were prepared by solid state reactions. The phases were characterized by powder X-ray diffractions (XRD), scanning electron microscopy, and thermal analysis. The XRD patterns of different members (x = 0.5, 0.7, 0.8, and 1.0) are consistent with pure phases crystallizing in the cubic PbS-type structure. The electrical characterization was carried out using ac impedance spectroscopy and dc methods. The temperature dependence of the dc conductivity shows typical semiconductor Arrhenius behavior. The impedance measurements were performed in the frequency range of 0.1 Hz to 10 MHz and at the temperature range of 15 °C to 350 °C. The ac conductivity conforms to Jonscher’s universal power law. The frequency dependence of the dielectric permittivity follows the normal dielectric material behavior, and the relaxation is thermally activated. The frequency and temperature dependences of the electrical data are found to follow Summerfield scaling formalism.     

Solid polymer electrolytes based on polystyrene‐polyether block copolymers having branched ether structure

To obtain solid polymer electrolytes (SPEs) having high ionic conductivity together with mechanical integrity, we have synthesized polystyrene (PSt)‐polyether (PE) diblock copolymers via one‐pot anionic polymerization. The PSt block is expected to aggregate to act as hard fillers in the SPE to enhance the mechanical property. The PE block consists of random copolymer (P(EO‐r‐MEEGE)) of ethylene oxide (EO) and 2‐(2‐methoxyethoxy) ethyl glycidyl ether (MEEGE) in different molar ratios ([EO]/[MEEGE] = 100/0, 86/14, 75/25, 68/32, and 41/59). The introduction of the MEEGE moiety in PEO reduced the crystallinity of PEO, and the fast motion of the MEEGE side chain caused plasticization of the PE block, thereby contributing to the fast ion transport. SPEs were fabricated by mixing the obtained diblock copolymer (PSE_x) and lithium bis(trifluoromethanesulfonyl) amide (LiTFSA) with [Li]/[O] = 0.05. Ionic conductivity of the obtained SPEs was dependent on the molar ratio of EO in the PE block (x) as well as the weight fraction of PE block (f_PE) in the block copolymer. PSE_0.86 (f_PE = 0.65) exhibited high ionic conductivity (3.3 × 10^?5 S cm^?1 at 30°C; 1.1 × 10^?4 S cm^?1 at 60°C) comparable with that of P(EO‐r‐MEEGE) (PE_0.85; f_PE = 1.00) (9.8 × 10^?5 S cm^?1 at 30°C; 4.0 × 10^?4 S cm^?1 at 60°C).     

Assessment of 1/f noise associated with nanopores fabricated through chemically tuned controlled dielectric breakdown

Recently, we developed a fabrication method—chemically-tuned controlled dielectric breakdown (CT-CDB)—that produces nanopores (through thin silicon nitride membranes) surpassing legacy drawbacks associated with solid-state nanopores (SSNs). However, the noise characteristics of CT-CDB nanopores are largely unexplored. In this work, we investigated the 1/f noise of CT-CDB nanopores of varying solution pH, electrolyte type, electrolyte concentration, applied voltage, and pore diameter. Our findings indicate that the bulk Hooge parameter (α_b) is about an order of magnitude greater than SSNs fabricated by transmission electron microscopy (TEM) while the surface Hooge parameter (α_s) is ∼3 order magnitude greater. Theα_s of CT-CDB nanopores was ∼5 orders of magnitude greater than theirα_b, which suggests that the surface contribution plays a dominant role in 1/f noise. Experiments with DNA exhibited increasing capture rates with pH up to pH ∼8 followed by a drop at pH ∼9 perhaps due to the onset of electroosmotic force acting against the electrophoretic force. The1/f noise was also measured for several electrolytes and LiCl was found to outperform NaCl, KCl, RbCl, and CsCl. The 1/f noise was found to increase with the increasing electrolyte concentration and pore diameter. Taken together, the findings of this work suggest the pH approximate 7–8 range to be optimal for DNA sensing with CT-CDB nanopores.     

Protein dielectrophoresis: Key dielectric parameters and evolving theory

Globular proteins exhibit dielectrophoresis (DEP) responses in experiments where the applied field gradient factor ∇E² appears far too small, according to standard DEP theory, to overcome dispersive forces associated with the thermal energy kT of disorder. To address this a DEP force equation is proposed that replaces a previous empirical relationship between the macroscopic and microscopic forms of the Clausius–Mossotti factor. This equation relates the DEP response of a protein directly to the dielectric increment δε⁺ and decrement δε⁻ that characterize its β-dispersion at radio frequencies, and also indirectly to its intrinsic dipole moment by way of providing a measure of the protein's effective volume. A parameter Γ_pw, taken as a measure of cross-correlated dipole interactions between the protein and its water molecules of hydration, is included in this equation. For 9 of the 12 proteins, for which an evaluation can presently be made, Γ_pw has a value of ≈4600 ± 120. These conclusions follow an analysis of the failure of macroscopic dielectric mixture (effective medium) theories to predict the dielectric properties of solvated proteins. The implication of a polarizability greatly exceeding the intrinsic value for a protein might reflect the formation of relaxor ferroelectric nanodomains in its hydration shell.     

Effects of dielectrophoresis on thrombogenesis in human whole blood

Thrombogenesis (blood clot formation) is a major barrier to the development of biomedical devices that interface with blood. Although state‐of‐the‐art chemically and pharmacologically mediated clot mitigation strategies are effective, some limitations of such approaches include depletion of active agents, or adverse reactions in patients. Increased clotting protein adsorption and platelet adhesion, which occur when artificial surfaces are exposed to blood result in enhanced clot formation on artificial surfaces. It is hypothesized that repelling proteins and platelets using dielectrophoresis (DEP), a contact‐free particle manipulation technique, will reduce clot formation in biomedical devices. In this paper, the effect of DEP on thrombogenesis in human blood is investigated. Undiluted whole blood from human donors is pumped through microchannels at a physiological shear rate (400 s ⁻¹). Experiments are performed by applying 0 V, 0.5 V_rms , 2 V_rms , and 3 V_rms to electrodes in the channel. Clot formation is observed to decrease in experiments in which DEP electrodes are active (average of 6% coverage @ 0V reduced to 0.08% coverage @ 3 V_rms ). Repulsion is more effective at higher voltages. DEP causes a quantifiable reduction in microscopic and macroscopic clot formation in PDMS microchannels.     

The origin of DC electrical conduction and dielectric relaxation in pristine and doped poly(3‐hexylthiophene) films

We present here the evidence for the origin of dc electrical conduction and dielectric relaxation in pristine and doped poly(3‐hexylthiophene) (P3HT) films. P3HT has been synthesized and purified to obtain pristine P3HT polymer films. P3HT films are chemically doped to make conducting P3HT films with different conductivity level. Temperature (77–350 K) dependent dc conductivity (σ_dc) and dielectric constant (ε′(ω)) measurements on pristine and doped P3HT films have been conducted to evaluate dc and ac electrical conduction parameters. The relaxation frequency (f_R) and static dielectric constant (ε₀) have been estimated from dielectric constant measurements. A correlation between dc electrical conduction and dielectric relaxation data indicates that both dc and ac electrical conductions originate from the same hopping process in this system. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1047–1053, 2010     

Spectroscopic,textural, electrical and magnetic properties of antimicrobial nano Fe(III) Schiff base complex

A novel Schiff base ligand (L) was prepared through condensation of 2,6‐diaminopyridine and dibenzoyl methane in a 1:1 ratio. This Schiff base ligand was used for complex formation reaction with Fe(III) chloride. The structures of the ligand and its complex were deduced from elemental analyses, mass spectroscopy, ¹H NMR, IR, UV‐Vis, electronic spectra, magnetic moment, molar conductivity measurements, thermogravimetric analyses and X‐ray diffraction. The molecular and electronic structures of both ligand and complex were optimized theoretically using density function theory (DFT) method. Moreover, the antimicrobial activities of the prepared compounds were studied and proven against some pathogenic bacteria. The Fe(III) complex had higher biological activity than that of the free ligand. Proceeding from the collected information, the properties of the complex were further investigated. The particle size was determined by dynamic light scattering technique to be 92.59 nm. Textural properties of the nano complex were studied by N₂ adsorption to estimate the specific surface area, pore volume and pore size distribution. The pores in the complex were found in the micropore–mesopore range. Differential scanning calorimetric measurements reveal the existence of four endothermic peaks at 243.8, 308, 339.8 and 380.5 K. Dielectric properties and conductivity were scanned at different frequencies and temperatures. The dielectric constant reaches a peak value of 600 at ~390 K, 30 Hz. A cross‐over from the universal dielectric response to the super linear power law of conductivity was reported for this complex at T ≤ 345 K. Finally, the AC‐magnetic susceptibility measurements were carried out in the low‐temperature region. The complex showed paramagnetic behavior with a slight change in the magnitude of its magnetic moment at T = 244 K.