Avance 3 300

All chemicals including media components were purchased from Sigma-Aldrich (St. Louis, MO), VWR (Radnor, PA) or Fisher Scientific (Pittsburgh, PA) and were used without further purification. HPLC analysis was performed using a Dionex Ultimate 3000 instrument equipped with a photo diode array (PDA) detector and the specified column (see below). LC-MS analysis was performed using an API 2000 electrospray ionization (ESI) mass spectrometer (AB SCIEX) connected to the HPLC system. Post-column splitting (1:4) was used to simultaneously monitor MS and uv-visible spectra. NMR spectra were obtained using Bruker Avance III 300 and Avance 500 spectrometers housed in the NMR Core Facility in the Department of Chemistry and Chemical Biology at the University of New Mexico. Chemical shifts (δ in parts per million) are reported relative to that of the solvent peak (δ = 2.50 ppm and 39.5 ppm for DMSO-d₆ in ¹H and ¹³C NMR spectra, respectively). High resolution MS data was obtained using a Waters LCT Premier ESI-TOF mass spectrometer housed in the Mass Spectrometry and Proteomics Core Facility in the Department of Chemistry and Chemical Biology at the University of New Mexico. Vector NTI Advance 10 (Life Technologies, Carlsbad, CA) was used for routine sequence analysis.

Commercially available chemicals, including 2-(4-bromophenyl)-4,6-diphenyl-1,3,5-triazine (TCI), 10,11-dihydro-5H-dibenz[b,f]azepine (TCI), 9,10-dihydro-9,9-dimethylacridine (TCI), phenoxazine (Alfa-Aesar), phenothiazine (TCI), potassium carbonate (Sigma-Aldrich), palladium(II) acetate (Sigma-Aldrich), tri-tert-butylphosphine (Sigma-Aldrich), and DMAC-Ph (TCI) were used without further purification, unless otherwise stated. All glassware, magnetic stir bars, syringes, and needles were dried in a convection oven at 120 °C. Reactions were monitored by using thin-layer chromatography (TLC). Commercial TLC plates (silica gel 254, Merck Co.) were developed, and the spots were visualized under UV irradiation at wavelengths of 254 or 365 nm. Silica gel column chromatography was performed with silica gel 60G (particle size 0.040–0.063 mm, Merck Co.). ¹H NMR (300 MHz) and ¹³C{¹H} NMR (126 MHz) spectra were collected with Bruker, AVANCE III 300 and 500 spectrometers, respectively. Chemical shifts were referenced to the peaks due to a residual solvent. Low- and high-resolution mass spectra were recorded by using an Agilent Technologies 6890 series mass spectrometer.

The samples for ¹H-NMR measurements were prepared by combining a specific number of moles of methane sulfonic acid (MSA) (CH₃SO₃H, Mw = 96.11 g/mol) with a specific mole number of distilled water ( ${\text{H}}_2\text{O}$ ; DW; Sigma Aldrich) in an argon glovebox. Each prepared sample was transferred to a standard 5 mm NMR tube (Boro-300-5-8; Deutero GmbH). A glass capillary with a diameter of 1 mm and an inner diameter of 0.8 mm was filled with Trimethylsilylpropanoic acid (TSP) in deuterium oxide ( ${\text{D}}_2\text{O}$ ; Sigma Aldrich, 99.9% atoms $\text{D}$ ) at a concentration of 0.02 mM and placed inside the 5 mm NMR tube. D₂O served as the frequency lock, and TSP was used as the chemical shift reference. The NMR samples were degassed by connecting the NMR tubes to a vacuum pump at 800 mb for 50 s while simultaneously sonicating them. The pressure was then raised to normal atmospheric pressure using dry argon. The ¹H-NMR spectra of the intracellular extracted samples, along with the two reference samples, were acquired using a broadband high-resolution 300.13 MHz NMR Bruker spectrometer Bruker Avance III 300 equipped with a room temperature NMR probe (BBO model-Bruker) at 293 K. The acquisition and processing of NMR spectra were analyzed using the Bruker TopSpin 3.5 software. The ¹H-NMR spectra were acquired using the standard 90° single-pulse experiment (Bruker pulse sequence $\text{zg}$ ).

Fourier-transform infrared spectroscopy (FTIR, Thermo spectrometer), thermogravimetric analysis (TGA, TA Instrument; model SDT Q600), field emission scanning electron microscopy (FESEM, TESCAN MIRA II microscope), X-ray diffraction (XRD, Philips PW1730), Zeta potential measurements (NanoBrook Pals Zeta Potential Analyzer), and nuclear magnetic resonance (NMR, 300 MHz Bruker Avance-III 300) have been utilized to characterize the hydrogel samples.