Network-supported and adaptable binding efficacy for flexible and multi-functionalized chitosan/phenolic carbaldehyde hydrogels

An Integrated Polysaccharide Hydrogel with Versatile Fluorescence Responses through Noncovalent Reformation of Gel Aggregation and for Bioimaging

“…We performed time-dependent density functional theory (TD-DFT) calculations at the CAM-B3LYP/6-31G level to investigate the photophysical properties of ChCrQ. These calculations reveal a D–A (donor–acceptor)-type electron transfer upon excitation. , In the enol form, the HOMO (highest occupied molecular orbital) localized on the N atom (from CrQ) donates electron density to the LUMO (lowest unoccupied molecular orbital) localized on the O atom (from −O–OH). This excitation shortens the O–H–N distance from 1.629 to 1.028 Å in the keto form, reflecting the formation of a strong N–H–O hydrogen bond in the excited state (S 1 ).…”

“…Hydrogel networks, as shown in the swelling study, 33,50 are susceptible to pH. 1,22,51 The emission properties of ChCrQ gels depend on the aggregation state of the CrQ moieties (either CrQ−CrQ or ChCrQ−ChCrQ interactions). The assembly of CrQ−CrQ aggregates is affected by variations in pH due to the reformation of gel networks at lower (protonation) and higher (proton abstraction) pH values.…”

“…22,23 p-Cresolbased quinazolinone aldehyde (compound c, CrQ) was synthesized using a synthetic approach using CuO nanoparticles as a catalyst. 24 This synthesis was carried out with compound b (1 mM) and anthranilamide (1 mM) catalyzed by 3 mol % copper oxide (CuO) nanoparticles dissolved in N,N-dimethylacetamide (DMAc, 3 mL) in air at 120 °C for 24 h. 1 S2a); ESI-MS (m/z): 281.08 (M+H) + (Figure S2b). Further, a 2% (w/v) chitosan (Ch) solution was mixed with CrQ (0.1 M) in a 2:1 ratio at 70 °C for the functionalized chitosan with p-cresol-based quinazolinone aldehyde (ChCrQ, compound d, Figure 1).…”

“…Conversely, the surrounding oxygen atoms are yellow, reflecting a negative potential due to the presence of lone pairs. 1,39 Figure 7c depicts the various intermolecular interactions among ChCrQ molecules. These interactions 52 include the steric effect (red), van der Waals interactions (green), and H-bonding (blue).…”

“…Carbohydrate-based hydrogels possess crucial and fundamental properties owing to the presence of a higher content of water molecules within their backbone . They exhibit a viscoelastic nature and intrinsic biocompatibility, effectively mimicking the cell matrix. , These remarkable assets have fueled a growing interest in fabricating functionalized hydrogels for environmental and health-based applications. , Bridging the gap between functionality and application necessitates investigating or optimizing the hydrogels’ structure/function relationship.…”