High molecular weight chitosan

Low viscosity sodium alginate (CAS Number: 9005-38-3); Brookfield viscosity 4–12 cps (1% in H₂O at 25 °C) was purchased from Sigma Aldrich (USA). High molecular weight chitosan (CAS Number: 9012-76-4, molecular weight: 310–375 kDa) was obtained from Sigma Aldrich (St. Louis, USA). A commercially available product calcium chloride, CaCl₂ was used as a calcium donating substance (Kemika, Zagreb, Croatia). All other chemicals were of analytical grade and used as received without further purification. Derivatives of dehydroamino acids were synthesized in the laboratory of professor Alexander Prosyanik (Dnipro, Ukraine).

All reagents were purchased from Sigma Aldrich unless otherwise indicated: ruthenium (III) chloride, sodium alginate, high molecular weight chitosan, acrylamide, MBAA, acetic acid, high molecular weight poly (vinyl chloride), valinomycin, bis(2-ethylhexyl) sebacate, tetraphenyl borate, cyclohexanone, N,N′-methylenebisacrylamide, and N,N,N′,N′-tetramethylethylenediamine. Filter paper and all pH buffer solutions were purchased from Fisher Scientific. A Wio Terminal microcontroller was purchased from Seeed Studio. A peristaltic pump and resistors were purchased from Cool Components. A 10 µF capacitor was purchased from RS Components. Arduino pH-4502C pH meter was purchased from Morden Store. Screen-printed electrodes were purchased from Saida Technology. Compost was purchased from Mokuzai. Finally, tomato seeds (Gardener’s Delight variety) were purchased from Thompson and Morgan.

Methanol (VWR International,
Radnor, Pennsylvania), ethanol, benzene (Carlo Erba Reagents, Milano,
Italy), H₂O₂ (30%), ammonia, formaldehyde, nitric
acid (65%), glycerol, sulfuric acid (95–98%) (all from Merck,
Rahway, New Jersey), phenol, high-molecular-weight chitosan (310–375 kDa;
≥75% deacetylated), lactic acid (85%), and sodium nitrite (97%)
(all from Sigma-Aldrich, St. Louis, Missouri) were of the analytical
grade purity. Pure O₂ (N5.0) was purchased from Messer
(Frankfurt, Germany). The chitosan blend (CHI) was prepared as follows:
1.5% (w/v) chitosan and 30.0% (w/w) glycerol were dissolved in 100.0 mL
of 1.0% (v/v) aqueous solution of lactic acid, and the mixture was
continuously stirred (Ika, Staufen, Germany) overnight at room temperature
(24 °C), as reported previously.^{49 (link)} Test solutions yielding the desired gaseous-phase H₂O₂ concentrations above the solution were prepared in 100.0
mL glass flasks according to Henryʼs law^{50 (link)} in the presence of the ambient atmosphere, i.e., no purging
was applied. The corresponding Henry constants were given in ref (50 (link)). All solutions used in
this work were prepared using water purified with the Elix 10/Milli-Q
Gradient unit (Millipore, Bedford).

High-molecular-weight
chitosan (CS, molecular weight of 310–375 kDa with ≥75%
deacetylation), sodium alginate (ALG), gold(III) chloride trihydrate
(HAuCl₄·3H₂O), 4-mercaptobenzoic acid (4-MBA),
melamine (MEL), salbutamol (SAL), and ractopamine hydrochloride (RAC)
were purchased from Sigma-Aldrich. Glacial acetic acid was purchased
from Carlo Erba. All of the reagents were used as received without
further purification. Deionized water was used throughout the experiments
and the rinsing process. The cellulose filter paper Whatman no. 1
with a 0.18 mm thickness was supplied from GE Healthcare Life Sciences.

Tenofovir Alafemaide was received as gift from GENIX PHARMA PVT. LTD., Pakistan. High-molecular-weight chitosan (>75% deacetylated, MW: 310,000–375,000 Da, 800–2000 cP, CAS number: 9012-76-4) was purchased from SigmaAldrich, Burlington, MA, USA. Polyethylene glycol (PEG) 6000 was purchased from Fluka Chemie GmbH, Germany. Thionyl chloride (SOCl₂, ≥99%), anhydrous tetrahydrofuran (THF, ≥99%, CAS number: 109-99-9), sodium tripolyphosphate (TPP, 85%, CAS number: 7758-29-4), phthalic anhydride (≥99%, CAS number: 85-44-9), sodium hydride (NaH, 60% dispersion in mineral oil, CAS number: 7646-69-7), hydrazine monohydrate (98%, contains 64% hydrazine, CAS number: 7803-57-8), anhydrous N,N-dimethylformamide (DMF, 99.8%, CAS number: 68-12-2), and anhydrous sodium hydroxide pellets (NaOH, ≥98%, CAS number: 1310-73-2) were purchased from Merck & Co., Inc., New York, USA, and pyridine (99.5%) was purchased from Riedel-de Haen. All reagents and solvents used in the synthesis process were of analytical grade. Deionized and double-distilled water was taken from a research laboratory of the University of Central Pharmacy, Pakistan.

High molecular weight chitosan (degree of deacetylation 65%), Genipin and C.I reactive black 5 (M_w: 991.82 g mol⁻¹) were purchased from Sigma Aldrich, Dorset, UK. Poly (vinyl alcohol), (PVA, M_w: 115,000) was purchased from BDH Limited Poole England and Hesperetin was purchased from Alfa Aesar, Lancashire, UK. The following chemicals were all obtained and used as reagents: sodium hydroxide, hydrogen peroxide, hydrochloric acid and ethanol. All chemicals were used without further purification.