Sodium dodecyl sulfate (sds)

All reagents used were HPLC grade or electrophoresis grade. Albumin, from bovine serum (BSA), urea, thiourea, 3-[(3-Cholamidopropyl) dimethylammonio]-1- propanesulfonate (CHAPS), β-mercaptoethanol, glycerol 86-88%, bradford reagent, coomassie blue R-250 (CBB), DL-dithiotreitol (DTT), iodoacetamide (IAA), trypsin sequencing trifluoroacetic acid (TFA), sodium deoxycholate (DOC) and acrylamide/bis-acrylamide 30% solution (37.5:1) were purchased from Sigma-Aldrich (St. Louis, USA). (N, N, N’, N’–tetramethylethylene-diamine (TMED), ammonium persulphate (APS), glycine were purchased from NZYTech (Lisbon, Portugal). Ampholytes pH 3–10, formic acid, and ammonium bicarbonate were purchased from Fluka (Steinheim, Germany). Hydrochloride acid (HCl), glacial acetic acid, tris-base, trichloroacetic acid (TCA), sodium dodecyl sulfate (SDS), methanol, acetonitrile were purchased from Panreac (Barcelona, Spain). Bromophenol blue was from Riedel-de Haën. Agarose and Mineral oil were purchased from Biorad (Hercules, USA).
Molecular weight marker for gel electrophoresis NZYColour Protein Marker II was purchased from NZYTech (Lisbon, Portugal). α-Cyano-4-hydroxycinnamic acid puriss for MALDI-MS from Fluka was used as MALDI matrix.

Ultrapure reagent-grade water was obtained from a Milli-Q system from Millipore/Waters. Gellan Gum (Gelzan^™, Gelrite^®), glass beads, lysozyme, deoxyribonuclease I (DNase), bromophenol blue, MES hydrate and MES sodium salt were acquired from Sigma-Aldrich Co. (St. Louis, MO, USA). Tris-base, tween-20, glycine, imidazole, sodium chloride (NaCl), nickel chloride hexahydrate (NiCl₂.6H₂O) and methanol were purchased from ThermoFischer Scientific (Waltham, MA, USA). Calcium Chloride dihydrate (CaCl₂.2H₂O) and sodium dodecyl sulfate (SDS) were obtained from PanReac Applichem (Darmstadt, Germany). β-mercaptoethanol and N,N,N′,N′-Tetramethylethylenediamine (TEMED) were acquired from Merck (Darmstadt, Germany). Bis-Acrylamide/Acrylamide 40% and NZYColour Protein Marker II were obtained from GRiSP Research Solutions (Oporto, Portugal) and NZYTech (Lisbon, Portugal), respectively. All other reagents and supplies were of analytical grade.

Doxorubicin hydrochloride (99.0%) was obtained from Yick-Vic Chemicals & Pharmaceuticals (Hong Kong, China). PLGA (Resomer^® 502H, lactide—glycolide ratio of 50:50, carboxylic end groups, Mw 7–17 kDa, η = 0.21 dL/g) was obtained from Evonik Industries AG (Darmstadt, Germany). Polyvinyl alcohol (PVA, 9–10 kDa, hydrolysis degree 80%) and the reference standards daunorubicin hydrochloride (EP CRS, 98.5%, EDQM) and Doxorubicin hydrochloride (EP CRS, 99.0%, EDQM) were purchased from Sigma-Aldrich Corporation (St. Louis, MI, USA). Poloxamer 188 (Kolliphor^® P188) was obtained from BASF SE (Ludwigshafen, Germany). Acetonitrile (99.9%), orthophosphoric acid (85.0%), and sodium dodecyl sulfate were purchased from PanReac Applichem (Darmstadt, Germany). All other reagents, including dichloromethane and dimethyl sulfoxide (DMSO), were qualified for analytical grade.

p-ABA (99% purity) from Sigma-Aldrich (Steinheim, Germany), vanillin (99%) from Sigma (Steinheim, Germany), and syringaldehyde (98%) from Aldrich (Steinheim, Germany) were used. Their standard solutions (25 mM in distilled water for p-ABA and 10 mM in ethanol (restificate) for the aromatic aldehydes) were prepared in 5.0 mL flasks by dissolving the exact weight of the substance. Ascorbic (99%), gallic (99%), and ellagic (95%) acids (Sigma, Steinheim, Germany) were used in the interference study. Their 10 mM (0.86 mM for ellagic acid) standard solutions were prepared in ethanol. The exact dilution was used for the preparation of less concentrated solution before measurements.
MWCNTs (outer diameter 40–60 nm, inner diameter 5–10 nm, and 0.5–500 μm length) from Aldrich (Steinheim, Germany) were used as a platform for the polymeric coverage deposition. A homogeneous 0.5 mg·mL⁻¹ suspension of MWCNTs was prepared in 1% sodium dodecylsulfate (Panreac, Barcelona, Spain) using 30 min of sonication in an ultrasonic bath (WiseClean WUC-A03H; DAIHAN Scientific Co., Ltd., Wonju-si, Korea).
Other chemicals were of c.p. grade and were used as received. All experiments were carried out at the laboratory temperature (25 ± 2 °C).

Ultrapure reagent-grade water was obtained from a Milli-Q system (Millipore/Waters, Etten-Leur, The Netherlands). Ammonium sulfate, ethylenediamine tetra-acetic acid (EDTA) and sodium dodecyl sulfate (SDS) were obtained from PanReac Applichem (Darmstadt, Germany). Hydrochloric acid and Tween-20 were purchased from ThermoFisher Scientific (Waltham, MA, USA). Sodium chloride was obtained from Honeywell (Charlotte, NC, USA) Sodium deoxycholate was acquired from Sigma-Aldrich Co. (St. Louis, MO, USA). Tris-base was obtained from Fisher Scientific (Epson, UK). Nonidet P-40 (NP-40) was purchased from Fluka (Monte Carlo, Monaco). Bis-Acrylamide/Acrylamide 40% was bought from GRiSP Research Solutions (Oporto, Portugal). The NZYColour Protein Marker II was acquired from NZYTech (Lisbon, Portugal). All chemicals were of analytical-grade commercially available and used without further purification.

Thymol (99.5% purity) and Thymolphthalein (95%) from Sigma (Steinheim, Germany) and carvacrol (98%) from Aldrich (Steinheim, Germany) were used. Their standard 10 mM solutions were prepared in methanol (c.p. grade) in 5.0 mL flasks. Ascorbic (99%), gallic (99%), caffeic (98%) and rosmarinic (98%) acids, quercetin dihydrate (95%) from Sigma (Steinheim, Germany), and chlorogenic acid (95%) from Aldrich (Steinheim, Germany) have been used in the interference study. Their 10 mM stock solutions in methanol were prepared in 5.0 mL flasks. The exact dilution was used for the preparation of less concentrated solutions.
MWCNTs (outer diameter 40–60 nm, inner diameter 5–10 nm and 0.5–500 μm length) from Aldrich (Steinheim, Germany) were used as a platform for further electrodeposition of polyThymolphthalein. A homogeneous 0.5 mg mL⁻¹ suspension of MWCNTs was prepared in 1% aqueous solution of sodium dodecyl sulfate (Panreac, Barcelona, Spain) by 30 min of sonication in an ultrasonic bath (WiseClean WUC-A03H (DAIHAN Scientific Co., Ltd., Wonju-si, Republic of Korea)).
All other reagents were c.p. grade and used as received.
The laboratory temperature was (25 ± 2 °C).