Akademik Veri Yönetim Sistemi
Micromachines, cilt.17, sa.4, 2026 (SCI-Expanded, Scopus)
This study reports the effect of polyethyleneimine’s molecular weight (PEI, Mn: 1200, 10,000, and 60,000 g/mol, denoted as PEI1.2, PEI10, and PEI60) on the physical, chemical, and biological characteristics of carbon dots (Cdots) derived from chitosan (Chi) and PEI (Chi-PEI Cdots). The size of Chi Cdots was 41.5 ± 6.1 nm, which increased to 50.9 ± 5.9, 71.4 ± 4.2, and 93.3 ± 7.4 nm with the preparation of Chi-PEI1.2, Chi-PEI10 and Chi-PEI60 Cdots. The fluorescence properties and quantum yield% values of the Cdots prepared from Chi, PEI1.2, PEI10, and PEI60 and their corresponding biopolymeric Chi-PEI Cdots were compared. A higher quantum yield of 26 ± 1.6% was observed for Chi-PEI1.2. This decreased with the increasing molecular weight of PEI and was calculated to be 15 ± 1.9% for Chi-PEI60. All the prepared bare Chi, bare PEI and corresponding bipolymeric Chi-PEI Cdots were observed to be nonhemolytic up to a 1 mg/mL concentration. Lower cytotoxic properties were observed for Chi-PEI Cdots on L929 fibroblast cells compared to their corresponding bare forms. Higher cell viability was observed for Chi-PEI1.2 Cdots with 95% viability in the presence of a 1000 µg/mL concentration. The antibacterial activity of the prepared Cdots against pathogens such as E. coli, K. pneumoniae, S. aureus, B. subtilis, and C. albicans was investigated and compared. Lower MIC and MBC values were determined for Chi-PEI10 against C. albicans with values of 12.5 and 50 mg/mL, respectively. Although the antibacterial properties of Chi-PEI Cdots were less strong than those of bare Cdots derived from individual Chi and PEI molecules, their light-induced antibacterial activities were found to be better.