Chemistry Department, Faculty of Science, Helwan University, Ain-Helwan, Cairo, 11795, Egypt.
Department of Pretreatment and Finishing of Cellulosic Based Textiles, Textile Research and Technology Institute, National Research Centre, Scopus Affiliation ID 60014618, 33 EL Buhouth St., Dokki, Giza, 12622, Egypt.
Sci Rep. 2024 Nov 25;14(1):29226. doi: 10.1038/s41598-024-80222-7.
The current study represents a unique fabrication strategy for preparation of fluorescent hydrogels via incorporation of fluorescent quantum dots (QDs) as fluorophore entities into chitosan as a gelling matrix. QDs identified as carbon quantum dots (CQDs) & nitrogen containing carbon quantum dots (NCQDs) were preliminary synthesized from cellulose nanocrystals (CNCs) and cationic cellulose nanocrystals (CCNCs), respectively. Cationic CNCs was prepared via chemical grafting with poly-di-allyl dimethyl ammonium chloride (CNCs-g-poly-DADMAC) through free chain polymerization reaction. Additionally, both of the prepared CQDs & NCQDs were impregnated in 3D interpenetrating network of chitosan for preparation of microbicide/florescent hydrogels (CQDs@Chs hydrogel & NCQDs@Chs hydrogel). The represented data revealed that, exploitation of cationic CNCs resulted in preparation of NCQDs with more controllable size and superior photoluminescence. Moreover, the increment in concentration of CNCs reflected in nucleation of enlarged QDs, at variance of CCNCs, whereas, increment of concentration resulted in significantly smaller-sized QDs. Size distribution of CQDs ingrained from 2% CNCs was estimated to be 8.2 nm, while, NCQDs ingrained from 2% CCNCs exhibited with size distribution of 3.8 nm. The prepared florescent CQDs@Chs hydrogel & NCQDs@Chs hydrogel showed excellent antimicrobial performance and the diameter of inhibition zone was estimated to be 31 mm, 26 mm & 22 mm against E. Coli, S. Aureus & C. Albicans with CQDs@Chs, respectively. Whereas, treatment of the as-mentioned microbial strains with NCQDs@Chs resulted in detection of inhibition zone diameter to be significantly higher as 34 mm, 28 mm & 25 mm for E. Coli, S. Aureus & C. Albicans, respectively. In a conclusion, cationic CNCs showed seniority in nucleation of QDs with significantly higher photoluminescence and microbicide activities.
当前的研究代表了一种独特的制备策略，通过将荧光量子点（QDs）作为荧光团实体掺入壳聚糖中作为凝胶基质来制备荧光水凝胶。量子点被鉴定为碳量子点（CQDs）和含氮碳量子点（NCQDs），分别初步从纤维素纳米晶体（CNCs）和阳离子纤维素纳米晶体（CCNCs）合成。阳离子 CNCs 通过与聚二烯丙基二甲基氯化铵（CNCs-g-poly-DADMAC）的化学接枝反应，通过游离链聚合反应制备。此外，两种制备的 CQDs 和 NCQDs 都被浸渍在壳聚糖的 3D 互穿网络中，用于制备杀微生物剂/荧光水凝胶（CQDs@Chs 水凝胶和 NCQDs@Chs 水凝胶）。所代表的数据表明，利用阳离子 CNCs 可以制备出具有更可控尺寸和更高光致发光性能的 NCQDs。此外，CNCs 浓度的增加反映了较大 QDs 的成核，而与 CCNCs 不同的是，浓度的增加导致 QDs 的尺寸显著减小。从 2%CNCs 中嵌入的 CQDs 的尺寸分布估计为 8.2nm，而从 2%CCNCs 中嵌入的 NCQDs 的尺寸分布为 3.8nm。制备的荧光 CQDs@Chs 水凝胶和 NCQDs@Chs 水凝胶表现出优异的抗菌性能，对大肠杆菌、金黄色葡萄球菌和白色念珠菌的抑菌圈直径分别估计为 31mm、26mm 和 22mm。然而，用 NCQDs@Chs 处理上述微生物菌株，检测到的抑菌圈直径分别显著更高，大肠杆菌为 34mm、金黄色葡萄球菌为 28mm、白色念珠菌为 25mm。总之，阳离子 CNCs 在 QDs 的成核中表现出优越性，具有更高的光致发光和杀微生物活性。
