Milli q reagent grade water system

The anticancer drugs, epirubicin (EPI), idarubicin (IDA), and daunorubicin (DAU), were received from Selleckchem (Houston, TX, USA), and doxorubicin (DOX) was purchased from Sigma-Aldrich Co. (St Louis, MO, USA); the drugs were used as received. The apoferritin from equine spleen (APO) was purchased from Sigma-Aldrich Co. (St Louis, MO, USA). N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC), N-hydroxysuccinimide (NHS), folic acid, and other chemicals were obtained from Aldrich Chemical Co. (Milwaukee, WI, USA) and were of analytical grade and used as received. Phosphate-buffered saline (PBS) pH 7.4 consisted of 1.8 mM Na₂HPO₄, 137 mM NaCl, 2.7 mM KCl, and 10 mM KH₂PO₄. McIlvain buffer (MI buffer) solutions (pH 3.6, 4.6, and 5.6) were prepared from 0.2 M Na₂HPO₄ and 0.1 M citric acid stock solutions. All aqueous solutions were prepared with deionized water (resistivity of 18.2 MΩ cm) purified with a Milli-Q reagent grade water system (Merck Millipore, Billerica, MA, USA).

The microplastics used in this study were Latex Microsphere Suspension 7520A (PS; polystyrene particle; average diameter 19 µm; coefficient of variation, ≤16%; liquid suspension; concentration, 10% solids by weight (w/w); density 1.05 g/mL) from Thermo Fisher Scientific (Tokyo, Japan), Polyethylene Microsphere CPMS-0.96 20–27 µm (PE; polyethylene particles; diameter range, 20–27 µm; particles within this diameter range, >90%; dry; density, 0.96 g/mL) from Cospheric (Santa Barbara, CA, USA), and Polypropylene Microsphere PPS-WHT-0.9 2.45 ± 0.05 mm (PP; polypropylene particles; diameter, 2.45 ± 0.05 mm; dry; density, ~1 g/mL) from Cospheric. The fluorescent SPHERO Ultra Rainbow Fluorescent Particles URFP-100 (diameter, 8.0–12.9 µm; concentration, 1 × 10⁷ particles/mL; Thermo Fisher Scientific) were used as the fluorescent standard. The fluorescent dyes Nile Red, Fluorescein, and Rhodamine 6G were obtained from Fujifilm Wako. All aqueous solutions were prepared with deionized and charcoal-treated water (specified resistance >18.2 MΩ cm), obtained using a Milli-Q reagent-grade water system (Merck Millipore; Bedford, MA, USA).

All solvents were high performance liquid chromatography grade and were used without modification. All standard compounds were purchased from Sigma-Aldrich (St. Louis, MO, USA). Formic acid, methanol and acetonitrile were obtained from Merck (Merck KGaA, Darmstadt, Germany). Distilled water was produced by a Milli-Q reagent-grade water system (Millipore; Billerica, MA, USA). UPLC was performed on a Thermo Fisher Accela system and mass spectrometry was performed on an LTQ Orbitrap XL hybrid mass spectrometer (both from Thermo Fisher Scientific, Franklin, MA, United States).

MCH, K₃[Fe(CN)₆] and K₄[Fe(CN)₆], PBS buffer and MgCl₂ were purchased from Sigma-Aldrich (Poznan, Poland). Potassium hydroxide, sulfuric acid, ethanol and methanol were obtained from POCh (Gliwice, Poland). Alumina slurries with particle sizes of 0.3 and 0.05 µm were produced by Buehler (Lake Bluff, IL, USA). The Apt-RBP-4 sequence of: 5’-ACA GTA GTG AGG GGT CCG TCG TGG GGT AGT TGG GTC GTG G-3’, functionalized with a thiol group (-SH) at its 5’-end, was purchased from Biomers (Ulm, Germany). The aptamer sequence was taken from a paper by Lee and co-workers. RBP-4 was obtained from Abcam (ab111460). Vaspin (SRP4915) and adiponectin (SRP4901) were purchased from Sigma-Aldrich. All aqueous solutions were prepared with deionized and charcoal-treated water (resistivity of 18.2 MΩ cm) filtered with a Milli-Q reagent-grade water system (Millipore, Bedford, MA, USA). Before each measurement, all solutions were purged with nitrogen (ultrapure 6.0, Air Products, Warsaw, Poland) for 10 min in order to remove oxygen.

The DPM-AR (Scheme 1B) and the terpyridine-NHS (TPY–NHS) were synthesized at the Department of Chemistry, KU Leuven, Leuven. The procedure for synthesis was briefly described in the Supplementary Materials (Scheme S1) [23 (link)]. AHT, MBL, cobalt (II) acetate Co(OAc)₂, dichloromethane (DCM), sodium chloride (NaCl), sodium sulfate (Na₂SO₄), sodium bromide (NaBr), sodium nitrate (NaNO₃) and boric acid (H₃BO₃) were purchased from Sigma-Aldrich (Poznań, Poland). Potassium hydroxide (KOH), sulfuric acid (H₂SO₄), nitric acid (HNO₃) and methanol (MeOH) were obtained from Avantor Performance Materials (Gliwice, Poland). All reagents were of analytical grade. All aqueous solutions were prepared with deionized and charcoal-treated water (resistivity of 18.2 MΩ cm) purified with a Milli-Q reagent grade water system (Millipore, Bedford, MA, USA). These solutions were deoxygenated by purging with nitrogen (ultrapure 6.0, Air Products, Warszawa, Poland) for 15 min.