1 Introduction

The phenomenon of magnetic hyperthermia (MHT), which happens when magnetic nanoparticles (MNP) are targeted to an alternating magnetic field (AMF), is one new and exciting use of MHT [1]. The HT is produced by MNP-mediated conversion of the AMF energy into induction heating, which may be fruitful in some categories of cancers due to the targeted thermal extermination of tumor cells with minor collateral destruction. Furthermore, HT is regarded as a non-invasive treatment for oncological pathologies in which carcinoma and healthy cells of living tissues are triggered to cell damage, necrosis, and apoptosis [2,3,4]. High-frequency hyperthermia (HFHT), including microwave-HT, radiofrequency-HT, and with radiation or chemotherapy [5], is frequently used as treatment for sophisticated cancers in many nations. Superparamagnetic iron oxide nanoparticles Fe3O4 (SPIONs) have major role in important applications in biomedicine, activated by AMF that is employed in targeting certain areas of the human body used in magneto-thermal, MHT and drug delivery. A recent study revealed a huge potential for this technique to manipulate fluid viscosity under flowing conditions, which might be employed by many sectors in addition to the well-known medical uses [6].

SPIONs coated with polyethylene glycol (PEG) exhibit favorable intrinsic physic-chemical properties, high hydrophilicity and flexibility, low immunogenicity and toxicity, and adjustable superior magnetic characteristics [7,8,9,10], making them suitable for theranostic and HT agents. The utilization of NPs as well as the intensities of both applied laser and external MF may be reduced if they are concentrated in the tumor location rather than the surrounding area. Neel and Brownian relaxation cause heat to be produced primarily when MF is exposed to external AMF in the MHT technique [11, 12]. MNP-based HT therapy has gained much attention due to its capacity to target and heat inactivate bacterial pathogens and cancer cells in a minimally invasive manner [13, 14]. According to the data, cancer cells are more sensitive to temperatures exceeding 41 °C than normal cells, another emerging treatment for malignant cancer [15, 16] involves the removal of cancer cells at optimal heating between 41 and 46 °C using thermal energy released by MNPs under external AMF.

1.1 Specific absorption rate (SAR)

SAR calculates the MNPs capacity to absorb AMF energy and produce heat energy. It typically refers to the conversion of magnetic energy into HT [17]. SAR technique is the rate at which electromagnetic radiation (or RF) is absorbed by the biological substance per mass unit, is the primary factor regulating tissue heating. It is proportional to the temperature rate increase (∆T/∆t) and is measured in watts per kilo gram in Eq. (1):

$$\mathrm{SAR}= {C}_{\mathrm{e}} \left(\frac{\Delta T}{\Delta t}\right) \left(\frac{{m}_{\mathrm{s}}}{{m}_{\mathrm{m}}}\right)\dots$$
(1)

where Ce is the capacity of specific heat suspension equal to 4.186 J/g, ms is the mass of suspension, mm is the mass of the magnetic material in suspension, and \(\Delta\)T/\(\Delta\)t is the beginning slope of the thermal-time plot in the linear zone [18, 19].

1.2 Application of Arduino microcontroller

Arduino microcontroller is a type of embedded integrated circuit on a straightforward board with a configuration for open-source development that enables computers to direct initiatives that are both artistic and practical. The firmware and essential programming language used by Arduino are stored on the chip. However, it's feasible for non-experts without any programming knowledge to adopt and use the Arduino boards. Arduino shingle technology software and hardware [20], which have this as their main advantage.

In this paper, we investigate the implementation of a newly designed system that uses a set-up connected to an Arduino program to display the magnetic field range in the solenoid copper coil. The high-frequency rate is displayed on the lab top to improve the magnetic HT applications. Apply AMF to magnetic fluid based on MNPs that have high MS with different concentrations to enhance the SAR values. The present study of the program system that improves the HT rate helps to realize the required SAR values, although the setup computed via the Arduino microcontroller program will help the scientific researchers use it in the future to apply the magnetic HT in both in-vitro and in-vivo magnetic fluid calorimetric approaches.

2 Materials and methods

2.1 Synthesize of superparamagnetic NPs

The preparation of SPIONs coated with polyethylene glycol Fe3O4@PEG was carried out by the sonochemical method as reported in our previous work [21].

2.2 Hardware and software for HT set-up

Set-up and loop components make form the basic programming structure for the Arduino microcontroller, it was chosen because it is widely available and circulated, simple to program and control, and inexpensive. All variables needed to set the pin mode or serial communication are stated and defined in the setup components. The Arduino board is changed, responded to, and controlled by the loop components, allowing the coded script to interact [18]. In addition to analogue inputs, the Arduino features fourteen digital I/O pins: A 16 MHz crystal oscillator; the ability to power the Arduino Uno through USB or an external power source (9-V battery); and the ability to configure pin 3 of the serial header in-circuit. Through the modifying, responding, and controlling of the Arduino board, the loop combination enables the coded script to relate to one another [22]. The input for frequency is connected to digitalRead (pin 5) and tracked to the input (16-bit) hardware counter1's alternate port function (T1). More counter overflows are counted and calculated as the resolution is increased, adding the counter value to the long integer result at the end. A single transistor or a 74HC14 inverter, for example, can be used to amplify weak signals if the frequency source (coil) output is digitally leveled. Approximately 8 MHz is the maximum input frequency when the signal duty cycle is 50%. In the start digitalRead () function, the gate time for the counting period can be selected. Values of 10, 100, or 1000 mS are workable for a resolution of 100, 10, or 1 Hz, but any value may be used. The wiring script that was installed on the Arduino Uno used in all of the experimental tests is shown in Fig. 1.

Fig. 1
figure 1

The set-up program script

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2.3 Set-up and AMF hyperthermia

It is set to a high frequency and operates at a voltage of DC 24–36 V with a current of 15–30 A, for example, in a 24 V 350 W switching power supply. The manufacturer of ZVS is (Aihaozhe Elec, Hong Kong, China) it's cooled by a circulating cooling water pump and connected by a copper coil that has seven turns of an inner diameter of 3.8 cm. The MF creation inside the solenoid coil using a digital DC power supply running at 24 V and 14 amps, and the frequency range of 300 kHz. An oscilloscope was used to adjust and measure the output power at a varied frequency from the ZVS circuit. The intensity of the generated MF was detected with a simple magnetometer and compared with the results of the output power of the oscilloscope. The frequency counter developed by the Arduino microcontroller program system and it displays the frequency levels.

2.4 Magnetic induction heating system

Magnetic induction heating set-up with the solenoid coil produces MF within the coil (Fig. 2). The designed solenoid encompasses the full sample volume in a homogeneous field to guarantee reliable readings of SAR [23]. Along with other design features, coil has seven turns made from cylindrical copper plate sections, which improves its performance over a solenoid of a similar size.

Fig. 2
figure 2

Block diagram of system device (created in Biorender.com)

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MNPs with concentrations (5, 10, and 20 mg/ml) dissolved in 1 ml of ultrapure water was placed in 2.5 mL microcentrifuge tube and fixed by holder inside the center coil without influencing the walls or touching or moving the sample. The rise in sample heating was monitored and recorded every 1 min using Seek thermal cameras with compact heating. An internal water cooling circulation was used to keep coil temperature at room temperature. The following formula, which was derived from (2), was used to calculate magnetic field (H) value in the solenoid coil for MNPs heating ability [24].

$$B = \mu { }\left[ {\left( {\frac{{NI_{{{\text{rms}}}} }}{2l}} \right)\left( {\frac{{ - z + \frac{l}{2}}}{{\left[ {\left( {z - \frac{l}{2}} \right)^{2} + a^{2} } \right]^{\frac{1}{2}} }} + \frac{{z + \frac{l}{2}}}{{\left[ {\left( {z + \frac{l}{2}} \right)^{2} + a^{2} } \right]^{\frac{1}{2}} }}} \right)} \right],$$
(2)

where (μ) = 4π10−7 (H/m) is free space permeability, (N) is turns number, (L) is coil length, (Irms) is root mean square, and (a) is coil radius.

3 Results and discussion

Surface morphology and transmission electron microscope (TEM).

The morphology and diameter of Fe3O4@PEG NPs were measured by using scanning electron microscopy (SEM) at high magnification, SEM scan shown the narrow size distributed spherical of particles at rang 12 nm (Fig. 3A) as reported in [25]. The Fe3O4@PEG sample are approximately spherical and slight agglomeration of primary particles that prepared with Fe3O4 to PEG, furthermore, a significant decrease in aggregation between the smaller NPs. Figure 3B explained the TEM image of Fe3O4@PEG synthesis appear broad because the crystallite size is too small [21], it is obtained fine SPIONs. Because of their magnetic properties, MNPs contain aggregated NPs average size is 14 nm and geometric shape appears to be cubic.

Fig. 3
figure 3

A. SEM scan, B. TEM, C. VSM, D. XRD, and E. is the characteristic temperature time plot obtained

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3.1 Magnetic properties measurements

The magnetic hysteresis loop is clarified in Fig. 3C and Table 1, for the SPIONs under investigation. A small area of Fe3O4@PEG exhibits SPIONs behavior as shown by the loops; it is clear that the magnetization saturation (MS) decreased the smaller size. Due to its extremely tiny size, highest MS, and good homogeneity, the Fe3O4@PEG was shown to be the most beneficial in HT according to the data from the M-H loop [19].

Table 1 Magnetization saturation value (MS), Remanent magnetization, (Mr/Ms), loop area, and D
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3.2 X-ray diffraction (XRD)

According to Fig. 3D, the XRD charts were indexed and compared to ICDD card 04-015-8207, the Fe3O4@PEG crystallized in a cubic spinel structure in a single spinel phase with space group Fd3m. XRD peaks look broad because the crystallite size is too small, and fine SPIONs were produced. The Fe3O4@PEG crystallized satisfactorily in cubic spinel form in a single phase without the need for further heat treatment. In the (220), (311), (400), (44 0), and (511) planes, distinct diffraction peaks were seen [21]. So, Bragg inter-planar distance of the crystal and is estimated from diffraction Eq. (3),

$$2d\sin \theta = n\lambda ,$$
(3)

and the density theoretical was computed from Eq. (4) [26],

$$D_{x} = \frac{ZM}{{NV}},$$
(4)

where N is Avogadro’s number, Z is the molecules per unit cell number, M is the molecular weight, and V is the unit cell volume (V = a3) in cubic symmetry case. From the Scherrer's Eq. (5) can be calculate the crystallite size (D) because all of the diffraction profiles exhibit broad profile distribution as a result of X-ray scattering from small nanocrystals:

$$D = \frac{k\lambda }{{\beta \cos \theta }},$$
(5)

where λ = 1.54 Å, k Scherer constant = 0.90 for spherical crystals, and is the corrected full width at half maximum (FWHM) of a peak profile, so the crystallite size was found to be 9.7 nm (Table 1).

3.3 Set-up thermal heating management results

The magnetic heating experiments were carried out using a frequency of 300 kHz, yielding 2.8 mT AMF (HF = 0.9 × 109 Am−1 Hz) [27,28,29]. The set-up is calibrated in the biotechnology department compared to a standard device and controlled by a special program. The Arduino IDE was used to upload the code to the board after all the wires had been connected. The copper coil exposes samples to 2D field amplitude fluctuations by providing a uniform MF of HT in a constrained volume inside the coil [30]. The solenoid coil operates with current field strength and is thus qualified for generating a uniform MF within a sizeable portion of the coil when the power is high [31]. This set-up is unusual in HT since it combines these system elements and links for MF and frequency detections [32], and that can be modified for MF calorimetric. The findings showed that the standard inductor geometry utilized for single cell cultures or small animals is the solenoid coil.

3.4 Magnetic induction heating and SAR evaluation

By capturing time-dependent temperature curves from magnetic induction heating experimental observations, the heating effectiveness of Fe3O4@PEG was examined for 15 min. Figure 3E displays the time-dependent temperature characteristic curves. Fe3O4@PEG NPs fluid was evaluated at concentrations of 5, 10, and 20 mg/mL, and its capacity for induction heating was investigated at a frequency of 250–300 kHz. Once heat creation and heat loss to the environment by the NPs are balanced, the temperature of the NPs rises quickly at first, then gradually, and finally reaches a maximum [33]. The HT of the MNPs was discovered to be highly reliant on the MNP content, magnetic characteristics, and setup MF. Figure 4A displays the thermal images of Fe3O4@PEG taken by a Seek thermal compact camera with scale. Figure 4B describes the SAR values and evolution of thermal-time for a Fe3O4@PEG sample with different concentrations under a MF. SAR is evaluating the heat produced by MNPs under MF, which was calculated using Eq. (1), with the higher heating temperatures at 20 mg/mL (TS) being 47 °C. SAR values for samples were reported in Table 2 to be 188, 217, and 234 W/g at concentrations of 5, 10, and 20 mg/ml respectively. Figure 4C includes the control samples (solution with and without NPs) for comparison purposes.

Fig. 4
figure 4

A Thermal images at initial for (20 mg sample) captured at multiple time scales, B SAR values, and C solution with and without NPs

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Table 2 SAR values at various concentrations (5, 10, and 20 mg/ml)
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Table 3, explain comparison between our SAR results and others scientific reported for MNPs and found that they were higher in comparison with Fe3O4 colloids suspended in water 15, 0.5 mg at 184, 13.3 kHz, respectively[34, 35]. However, the SAR values are lower than [36] due to multi-core Fe3O4, where they used a high current field strength of 26.7 and 38kA/m, respectively. The supplied data in Table 3 made the impressive SAR values apparent [37,38,39] due to the high-frequency rate, number of turns, high current used, and narrow diameter of copper coil.

Table 3 Reported literature on MNPs, coil design, frequency, current, and SAR value
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The present work uses a new system with a few number of turns with copper coil narrow diameter to get an ideal value for HT that is controlled and computed by a special program. The SAR obtained from MNPs was concluded to be field-amplitude dependent and a critical variable for thermal therapy. Fe3O4@PEG NPs at a concentration of 20 mg/ml are evidently promising candidates for their employment as thermal agents in MFH in order to sustain the required range of therapeutic heating for a sufficient amount of time, as shown by the comparison of SAR values [38,39,40,41,42,43].

4 Conclusion

In this research, in a short period of time, the set-up achieved a high-frequency HT and appropriate SAR values. The high frequency output was computed and developed by the frequency counter Arduino microcontroller program system that able to display the frequency levels and the fluctuations rate inner the coil. The set-up enhanced the measurement of frequency rate and high-frequency hyperthermia (HFHT) using Arduino in the coil and simulations of the MNPs HT. Our system showed a distinguished potential mainly to measure SAR for SPIONs in magnetic fluid calorimetric systems in the future. The set-up can be utilized in medical application tests both in vitro and in vivo based on the concentration, MS, and crystal size of the NPs are the main parameters controlling their induced magnetic heating.