Chromasolv plus

Imidazole >98% and 1,4,5,8-naphthalenetetracarboxylic dianhydride (>95%) were purchased from TCI Europe N.V. Toluene, hydrochloric acid, 96% ethanol, and methanol were obtained from Avantor Performance Materials Poland. Chloroform-D (CDCl₃), n-aliphatic amines, n-heptane, Toluene (CHROMASOLV^® (Honeywell, Charlotte, NC, USA), for HPLC, 99.9%), 1,2-dichlorobenzene (for HPLC, 99%), and chloroform (CHROMASOLV^®Plus, (Honeywell, Charlotte, NC, USA), for HPLC, >99.9%) were supplied by Sigma-Aldrich, Darmstadt, Germany. All reagents and solvents were used as received. The OFETs were prepared using silicon substrates with 230 nm silicon dioxide gate dielectric with prepatterned Au/ITO (20 nm/10 nm) electrodes (Fraunhofer Gen. 4 OFET substrates (Fraunhofer IPMS, Dresden, Germany)). The OFET channel width (W) and the length were 10 mm and 10 μm, respectively.

Propane-2-ol (PrOH, for HPLC, ≥99.9%), acetonitrile (ACN, gradient grade, for HPLC, ≥99.9%), diethylamine (DEA, ≥99.5%), 2-propylamine (IPA, ≥99.5%), triethylamine (TEA, ≥99%), trifluoroacetic acid (TFA, 99%), and acetic acid (ReagentPlus^® > 99%) were supplied by Sigma–Aldrich (St. Louis, MO, USA). Methanol (MeOH, supergradient grade, for HPLC, ≥99.9%) and ethanol absolute (EtOH, gradient grade, for HPLC, >99.7%) were purchased from VWR International (Radnor, PA, USA). Water (Chromasolv Plus, for HPLC) was obtained from Honeywell (Charlotte, NC, USA). Pressurized liquid CO₂ 4.5 grade (99.995%) was purchased from Messer (Prague, Czech Republic). Chiral compounds: pyrovalerone, cathinone, ketamine, and amphetamine derivatives were purchased from internet vendors and tested for identity prior to use. Modafinil was purchased from Carbosynth Ltd. (Compton, United Kingdom). Chlorthalidone, citalopram, and praziquantel were supplied by Sigma–Aldrich (St. Louis, MO, USA). The list of compounds used in this work with their structures is given in Table S1 in the Supplementary Material.

For the preparation of the hydrogel samples and CaCl₂ solution, we used the following ingredients:

0.3 g. Alginic acid sodium salt from brown algae, middle viscosity, Sigma-Aldrich (Burlington, MA, USA).

0.3 g. Methyl Cellulose, viscosity 4000 cP, 2% in H₂O (20 C) (lit.); Sigma-Aldrich (Burlington, MA, USA).

0.3 g Laponite RD; BYK.

10 mL deionized water CHROMASOLV™ Plus, for HPLC; Honeywell (Charlotte, NC, USA).

Calcium chloride, anhydrous, granular; 96%, Sigma-Aldrich (Burlington, MA, USA).

For crosslinking of the hydrogel, we used a solution of CaCl₂ with a concentration of 100 mmol/L; 1.2 g of CaCl₂ was diluted in 100 mL deionized water at 36 °C and mixed for 2 min with a magnetic stirrer.