Sonic 5

The total tellurium content was determined using the Elan 6100 DRC-e ICP-MS spectrometer (Perkin Elmer, Waltham, MA, USA). The ICP-MS apparatus was equipped with a standard ICP quartz torch, cross-flow nebulizer, and nickel cones. Table 1 presents operating parameters of the spectrometer. To separate the Te(IV) and Te(VI) species, a speciation apparatus set was applied. It consisted of an HPLC chromatograph (Perkin Elmer, USA) equipped with a Series 200LC Peltier oven, Series 200LC autosampler, and Series 200LC gradient pump. The sample from chromatographic column was introduced to ICP-MS by tubing system, automatic diverter and peristaltic pump. The diverter operates as an automatic switching valve to divert undesired portions of the eluate from the HPLC system to waste before the sample enters the ICP-MS. Soil samples were digested in a microwave oven (Microwave 3000, Anton Paar, Austria). Soil extractions were carried out using an ultrasonic cleaner (Sonic 5, Polsonic, Warszawa, Poland), and then the samples were centrifuged using a Beckman Coulter Avanti JXN-26 centrifuge (20,000 rpm, JA-25.50 Fixed-Angle Aluminum Rotor type).

It was possible to detect the produced porphyrins based on their extraction with MeOH:acetone (1:1, v/v). Extracellular porphyrins, which were excreted from the cells, were extracted from the growth medium supernatant after lyophilization (Thermo Electron Corporation, Heto PowerDry LL3000 Freeze Dryer) and sonication (Polsonic, Sonic-5) (10 min). After extraction of the porphyrins, their fluorescence spectra were determined using a Perkin Elmer Multimode Plate Reader EnVision® spectrofluorometer. The excitation wavelength was 405 nm. To induce endogenous porphyrin production, delta-aminolevulinic acid (1 mM) was added to the bacterial suspensions and cultured for 48 h at 37 °C with shaking (150 rpm).

ζ-potential measurements of synthesized SPIONs were carried out in disposable polystyrene cuvettes using a Zetasizer Nano ZS device (Malvern Panalytical, Malvern, UK) equipped with a dip cell with palladium electrodes (Malvern). Suspensions of different SPIONs were diluted with water to obtain the appropriate optical density for ζ-potential measurements and then briefly (~10 s) sonicated (ultrasonic cleaner Sonic-5, Polsonic, Warsaw, Poland) before the analysis. All measurements were conducted at 25 °C after 60 s of temperature stabilization and replicated three times per each type of NPs.

Plants used to obtain material for investigations come from the Medicinal Plant Garden at the Medical University of Białystok (Białystok, Poland) and were collected in June-August 2017–2020. Plants were carefully identified by one of the authors (M.T.), and individual voucher specimens were deposed at the Herbarium of the Department of Pharmacognosy, Medical University of Białystok (Białystok, Poland). Plant material was dried at room temperature in the shade and air temperature and subsequently finely ground with an electric grinder. Accurately weighed 2 g of each powdered dry plant material were separately extracted using an ultrasonic bath (Sonic-5, Polsonic, Warszawa, Poland) with 70% acetone at a controlled temperature (40 ± 2 °C) for 45 min in a 1:75 (w:v) solvent ratio to obtain raw extracts. Subsequently. extracts were evaporated to dryness, diluted with water (50 mL). and successively portioned between chloroform (10 × 20 mL). Afterwards. purified extracts were freeze-dried. The list of obtained aqueous acetone extracts from selected Potentilla species detailing plant species, voucher specimen, the parts used and extraction yields are presented in Table 4.

The TE extract used in the study is the same as described by Marcinczyk and co-authors (2017). It was prepared in the same extraction protocol, and can clearly correlate these two datasets. The powdered plant material (2.0 g) (batch number: 268.2020420.2020; Kawon, Gostyń, Poland) was extracted with 150 ml of 80% (v/v) methanol in an ultrasonic bath (Sonic-5, Polsonic, Poland) at a controlled temperature (40 ± 2°C) for 45 min. After solvent evaporation under reduced pressure and vacuum controlled temperature (Büchi System, Flawil, Switzerland) (temperature: 40 ± 2°C) the extract was suspended in water and subjected to lyophilization using a vacuum concentrator (Labconco, Kansas City, United States) until a constant weight of the extract was obtained (yield 0.89 g; 44.5%). Details of LC-ESI-MS analysis of the TE extract have been also described previously (Marcinczyk et al., 2017 (link)).