Chitosan,a natural cationic polysaccharide,is prepared industrially by the hydrolysis of the aminoacetyl groups of chitin,a naturally available marine polymer.Chitosan is a non-toxic,biocompatible and biodegradable po...Chitosan,a natural cationic polysaccharide,is prepared industrially by the hydrolysis of the aminoacetyl groups of chitin,a naturally available marine polymer.Chitosan is a non-toxic,biocompatible and biodegradable polymer and has attracted considerable interest in a wide range of biomedical and pharmaceutical applications including drug delivery,cosmetics,and tissue engineering.The primary hydroxyl and amine groups located on the backbone of chitosan are responsible for the reactivity of the polymer and also act as sites for chemical modification.However,chitosan has certain limitations for use in controlled drug delivery and tissue engineering.These limitations can be overcome by chemical modification.Thus,modified chitosan hydrogels have gained importance in current research on drug delivery and tissue engineering systems.This paper reviews the general properties of chitosan,various methods of modification,and applications of modified chitosan hydrogels.展开更多
Ni-mSA-mCS bipolar membrane （BM） was prepared by sodium alginate （SA） and chitosan （CS）, which were modified by Ca^2＋ and glutaraldehyde as linking reagents, respectively, mSA-mCS membrane was characterized by ...Ni-mSA-mCS bipolar membrane （BM） was prepared by sodium alginate （SA） and chitosan （CS）, which were modified by Ca^2＋ and glutaraldehyde as linking reagents, respectively, mSA-mCS membrane was characterized by FTIR, SEM, TG and used as a separator in the electrolysis cell to produce thioglycolic acid （TGA）. The experiment results show that TGAwas prepared effectively by electro-reduction of dithiodiglycolic acid （DTDGA） with the mixture of TGA and DTDGA in the cathodic chamber. The current efficiency was up to 66.7% at the room temperature （25 ℃） during the current density of 10 mA/cm^2. Compared with the traditional metal reduction method, the electro-reduction technology saves the zinc powder and eliminates the pollution to environment.展开更多
Photoelectrochemical(PEC) biosensors have shown great promise in bioanalysis and diagnostic applications in recent years. In this work, the CuO/Cu2O nanowire array(CuO/Cu2O Nanowire) supported on copper foam was prepa...Photoelectrochemical(PEC) biosensors have shown great promise in bioanalysis and diagnostic applications in recent years. In this work, the CuO/Cu2O nanowire array(CuO/Cu2O Nanowire) supported on copper foam was prepared as a photocathode for detection of tyrosinase though quinone-chitosan conjugation chemistry method. The in-situ generated quinones that were the catalytic product of tyrosinase acted as electron acceptors, which were captured by the chitosan deposited on the surface of the electrode. Direct immobilization of electron acceptor on the electrode surface improved the photocurrent conversion efficiency and thus sensitivity. The as-prepared biosensor can realize a rapid response in a wide linear range of 0.05 U/mL to 10 U/mL with the detection limit as low as 0.016 U/mL of tyrosinase. The current work provides a new perspective to design and develop highly sensitive and selective PEC biosensor.展开更多
文摘Chitosan,a natural cationic polysaccharide,is prepared industrially by the hydrolysis of the aminoacetyl groups of chitin,a naturally available marine polymer.Chitosan is a non-toxic,biocompatible and biodegradable polymer and has attracted considerable interest in a wide range of biomedical and pharmaceutical applications including drug delivery,cosmetics,and tissue engineering.The primary hydroxyl and amine groups located on the backbone of chitosan are responsible for the reactivity of the polymer and also act as sites for chemical modification.However,chitosan has certain limitations for use in controlled drug delivery and tissue engineering.These limitations can be overcome by chemical modification.Thus,modified chitosan hydrogels have gained importance in current research on drug delivery and tissue engineering systems.This paper reviews the general properties of chitosan,various methods of modification,and applications of modified chitosan hydrogels.
基金supported by the Nature Science Foundations of Fujian Province(No.D0710009)the Fujian Education Bureau(Nos.JB06069,JB05314).
文摘Ni-mSA-mCS bipolar membrane （BM） was prepared by sodium alginate （SA） and chitosan （CS）, which were modified by Ca^2＋ and glutaraldehyde as linking reagents, respectively, mSA-mCS membrane was characterized by FTIR, SEM, TG and used as a separator in the electrolysis cell to produce thioglycolic acid （TGA）. The experiment results show that TGAwas prepared effectively by electro-reduction of dithiodiglycolic acid （DTDGA） with the mixture of TGA and DTDGA in the cathodic chamber. The current efficiency was up to 66.7% at the room temperature （25 ℃） during the current density of 10 mA/cm^2. Compared with the traditional metal reduction method, the electro-reduction technology saves the zinc powder and eliminates the pollution to environment.
基金supported by the National Natural Science Foundation of China (21775089)the Outstanding Youth Foundation of Shandong Province (ZR2017JL010)+1 种基金the Key Research and Development Program of Jining City (2018ZDGH032)Taishan scholar of Shandong Province (tsqn201909106)。
文摘Photoelectrochemical(PEC) biosensors have shown great promise in bioanalysis and diagnostic applications in recent years. In this work, the CuO/Cu2O nanowire array(CuO/Cu2O Nanowire) supported on copper foam was prepared as a photocathode for detection of tyrosinase though quinone-chitosan conjugation chemistry method. The in-situ generated quinones that were the catalytic product of tyrosinase acted as electron acceptors, which were captured by the chitosan deposited on the surface of the electrode. Direct immobilization of electron acceptor on the electrode surface improved the photocurrent conversion efficiency and thus sensitivity. The as-prepared biosensor can realize a rapid response in a wide linear range of 0.05 U/mL to 10 U/mL with the detection limit as low as 0.016 U/mL of tyrosinase. The current work provides a new perspective to design and develop highly sensitive and selective PEC biosensor.
