## 2 Materials and Methods
### Characterization of the Microparticles  
The polymers are characterized in four stages. The first focuses on the polymerization process using FT-IR, FT-Raman spectroscopy, and thermogravimetric analysis (TGA). The second examines optical properties, including UV-Vis absorption, fluorescence spectroscopy, and particle size determination via granulometric analysis and SEM. FT-IR experiments were conducted using a JASCO FT/IR-6200 Type A instrument (JASCO Corporation, Tokio, Japan), while FT-Raman measurements were performed with a JASCO Laser Raman spectrometer (JASCO Corporation, Tokio, Japan). Thermal analyses were carried out with a Mettler Toledo TG-STDA instrument (Mettler Toledo, Greifensee, Switzerland), operating within a temperature range of 30-1000 \({}^{\circ}\)C at a heating rate of 5 \({}^{\circ}\)C/min in an air atmosphere. UV-Vis spectroscopic measurements were obtained using a Hewlett-Packard Agilent 8453 UV-Vis spectrometer (Agilent Technologies, Inc., Santa Clara, CA, USA), and fluorescence spectroscopy was performed with a Spex Fluorog 3-11 spectrofluorometer equipped with a 450 W xenon lamp (Horiba Scientific, Kioto, Japan), as the polychromatic light source. Particle size was performed using a JEOL 7001F SEM microscope (JEOL Ltd., Tokio, Japan), with polymeric samples coated in platinum.  
In the third step, the RB content in the microparticles was determined by hydrolysis of RB-linked in the polymer matrix and its subsequent quantification using UV-Vis spec  
Figure 1: Chemical structure of polymers P1 and P2 along with their respective synthetic process.  
Figure 2: Chemical structure of polymers P3 and P4 along with their respective synthetic process.  
troscopy. To carry out this analysis, in a round-bottom flask, 40 mg of polymer, 1 mL of 1,_A_-dioxane, and 300 uL of a tetrabutylammonium hydroxide (TBAOH) solution in MeOH (0.8 M) were introduced. The flask was sealed and stirred at room temperature for 24 h. Afterward, the polymer was filtered and washed with MeOH. The filtrate was transferred to a 10 mL volumetric flask and brought to volume with MeOH. The determination of the amount of hydrolyzed RB was calculated by the Beer-Lambert law (\(\lambda=557\)).  
The final stage of the characterization involves assessing the ability of the materials to generate singlet oxygen. The singlet oxygen production capability of the materials was evaluated by analyzing the photo-oxidation kinetics of anthracene-9,10-dipropionic acid (ADPA) in Milli-Q water. For each polymer sample, 25 mg of the photosensitizer was mixed with 10 mL of an ADPA solution (1.2 \(\times\) 10\({}^{-4}\) M) in a test tube. The heterogeneous mixture was stirred and equilibrated with air. The test tubes were then exposed to irradiation at room temperature using a 50 W halogen lamp placed 2 cm from the samples. Control experiments, both in the dark and without a photosensitizer, were conducted to evaluate any potential adsorption of ADPA onto the polymeric photocatalyst. Additional controls for polymers P1-P4 were performed under the same conditions without a photosensitizer, involving only ADPA irradiation and the use of Rose Bengal (5 uM) as a reference photosensitizer. The progress of the ADPA photo-oxidation was monitored using UV-Vis spectrophotometry for 60 min by tracking the decrease in the ADPA absorption band at 398 nm. At each time interval, the reaction was paused by turning off the lamp, a 1 mL aliquot was taken to measure its absorption spectrum, and then returned to the reaction mixture before irradiation was resumed.