## 3 Results and Discussion  
### Synthesis and Characterization of the Photoactive Microparticles  
The synthesis and characterization of the photoactive microparticles were reproduced as described previously. The following are the results obtained from the characterization of each photoactive material. P1--FT-IR (cm\({}^{-1}\)): 3018, 2917, 1629, 1425, 1265, 906, 795, 707. FT-Raman (cm\({}^{-1}\)): 3058, 2906, 1631, 1408, 1267, 1181, 1001. The decomposition temperature is 500-510 \({}^{\circ}\)C, and the average particle diameter is 24.2 \(\upmu\)m. P2--FT-IR (cm\({}^{-1}\)): 3020, 2920, 1625, 1453, 1266, 902, 794, 709. FT-Raman (cm\({}^{-1}\)): 3054, 2907, 1627, 1411, 1266, 1180, 1003. The decomposition temperature is 500-510 \({}^{\circ}\)C, UV-Vis absorption (\(\uplambda_{\max}\), nm): 571, fluorescence emission (\(\uplambda_{\max}\), nm): 602 (\(\uplambda_{\rm ex}\) = 572 nm), Rose Bengal loading: 2 \(\upmu\)mol RB g\({}^{-1}\) polymer, and the average particle diameter is 28.1 \(\upmu\)m. P3--FT-IR (cm\({}^{-1}\)): 3358, 3046, 2921, 1619, 1447, 990, 906, 798, 713. FT-Raman (cm\({}^{-1}\)): 3055, 2903, 1632, 1407, 1315, 1179,1105, 1003, 803. The decomposition temperature is 500-510 \({}^{\circ}\)C, UV-Vis absorption (\(\uplambda_{\rm max}\), nm): 561, fluorescence emission (\(\uplambda_{\rm max}\), nm): 593 (\(\uplambda_{\rm ex}\) = 564 nm), Rose Bengal loading: 2 \(\uplambda\)mol RB g\({}^{-1}\) polymer, and the average particle diameter is 24.5 \(\upmu\)m. P4--FT-IR (cm\({}^{-1}\)): 3367, 3056, 2928, 1628, 1451, 1081, 902, 804, 704. FT-Raman (cm\({}^{-1}\)): 3055, 2903, 1634, 1408, 1307, 1188, 1086, 1001, 930, 803. The decomposition temperature is 500-510 \({}^{\circ}\)C, UV-Vis absorption (\(\uplambda_{\rm max}\), nm): 562, fluorescence emission (\(\uplambda_{\rm max}\), nm): 591 (\(\uplambda_{\rm ex}\) = 564 nm), Rose Bengal loading: 2 \(\uplambda\)mol RB g\({}^{-1}\) polymer, and the average particle diameter is 28.8 \(\upmu\)m.  
FT-IR and FT-Raman characterization results confirm successful polymerization across all polymers. For P3 and P4, broad bands between 3100 cm\({}^{-1}\) and 3600 cm\({}^{-1}\) are observed, corresponding to N-H stretching from ethylamine and O-H stretching from hydroxyl groups of \(\gamma\)-gluconolactone, respectively. Detailed spectra are provided in the Supplementary Materials. The amount of covalently anchored Rose Bengal in all polymers was determined to be 2 \(\upmu\)mol of RB per gram of polymeric matrix, indicating that the addition reactions with ethylenediamine and \(\gamma\)-gluconolactone did not affect the covalently bound RB within the matrix. This value aligns with prior studies [31; 59], as well as particle size measurements obtained through SEM microscopy. On the other hand, as shown in Figure 3, the polymeric matrices P2, P3, and P4 exhibit the characteristic pink color of Rose Bengal, with P3 and P4 showing slightly brighter shades than P2. UV-Vis absorption spectra confirm the presence of RB in all polymers, with absorption maxima between 562 nm and 571 nm, consistent with previous studies in the literature [31; 59; 63]. The polymers display broader spectral profiles and longer wavelength shifts compared to free RB (\(\uplambda_{\rm max}\) = 557 nm), with P3 and P4 peaking at 561-562 nm and P2 at 571 nm. No leaching of RB was observed in any polymer when suspended in water. P2-P4 polymers demonstrated photoactivity in terms of singlet oxygen generation. The characterization study was conducted by assessing the materials' ability to generate singlet oxygen, which was determined by analyzing the kinetics of the model reaction of photo-oxidation of anthracene-9,10-dipropionic acid to form ADPA-O\({}_{2}\) endoperoxide (60 min, 1.2 \(\times\) 10\({}^{-4}\) M of ADPA in Milli-Q water), which is widely studied in aqueous media. The results obtained are as follows: P1--maximum conversion: 0%. P2--maximum conversion: 85%; K\({}_{\rm obs}\) (min\({}^{-1}\)): 0.0432. P3--maximum conversion: \(>\)99%; K\({}_{\rm obs}\) (min\({}^{-1}\)): 0.0635.