Recent development of chitosan-based polyelectrolyte complexes with natural polysaccharides for drug delivery.

Organization of Glucose-Responsive Systems and Their Properties

Lab of Biomimetic Electrochemistry and Biosensors, Institute of Physical Chemistry, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China; State Key Laboratory of Bioelectronics (Chien-Shiung Wu Laboratory), Southeast University, Nanjing 210096, China; MOE Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China

History and new developments of assays for cholinesterase activity and inhibition.

Enzyme immobilization on/in polymeric membranes: status, challenges and perspectives in biocatalytic membrane reactors (BMRs)

Amperometric glucose biosensor based on layer-by-layer assembly of multilayer films composed of chitosan, gold nanoparticles and glucose oxidase modified Pt electrode.

A rapid, simple method for fabricating glucose biosensors have been proposed for the efficient immobilization of enzymes and elimination of interferences at the same time. By using a single biopolymer chitosan on Pt electrode, first positively charged polyelectrolyte was constructed through glutaraldehyde as a cross-linking agent so that this kind of chitosan modified film can eliminate interference of possible electroactive compounds. Then another layer of chitosan was applied to immobilize enzyme glucose oxidase. The biosensor was operated at +0.600 V with a short response time (

Amperometric glucose biosensor based on chitosan with improved selectivity and stability

A potentiometric acetylcholinesterase biosensor based on pH-sensitive PVC membrane with plasma-polymerized ethylenediamine film has been proposed. Glow discharge plasma technique was utilized to deposit a film containing amino groups on the surface of pH-sensitive PVC membrane. Such an approach makes it possible to fabricate a very simple self-mounted acetylcholinesterase membrane directly attached to PVC pH-sensing electrode surface. The deposition conditions were optimized and the optimum plasma polymerization parameters were as follows: applied power, 75 W; pressure, 130 Pa; plasma exposure time, 60 min and flow rates, 10 ml min−1. Two neutral carriers, DOODA and DAMAB were compared as the pH-carrier, and the biosensor based on DAMAB showed better response characteristics. The effect of pH of the medium was also examined. The potential responses of biosensor increase with the acetylcholine chloride concentration over the concentration range of 10−6 to 10−1 mol dm−3 and the detection limit is 0.002 mmol dm−3 in pH 8.0 PB buffer solution. The biosensor was employed more than 200 times in 20 days while the maximum response span of biosensor retained 90%.

A potentiometric acetylcholinesterase biosensor based on plasma-polymerized film

Herein, a novel liquid crystal microarray (LCM) film with optical regulation ability is first constructed by combining liquid crystals (LC) and the highly ordered microporous structure of inverse opal photonic crystals (IOPhCs). The LCM films are fabricated by infiltrating LC molecules into the LC polymer with the structure of IOPhCs, and their properties are very different from those without the LC. Interestingly, the optical property of LCM films can be controlled by changing the orientation of LC molecules, which varies with the interfacial force. In combination with polarization images, spectral reflection peak, circular dichroism spectra, potential difference, and fluorescence images of LCM films, the mechanism of this change is investigated. It is found that the exposed basic group of single-stranded DNA is the key to the change of the optical property of LC microarrays. Meanwhile, the optical signals of LC microarrays based on the PhCs provide a novel LC signal mode for an LC sensing system (microspectral signal mode), and it can be recorded by a fiber-optic spectrometer, which is a great improvement on LC sensing signals. Therefore, the LC microarray sensing signal can be used for accurate analysis of targets by the change of the reflection peak intensity of PhCs. When the LC molecules are induced by different aptamers, the LC microarray sensing interface can be further used for the determination of different targets, such as cocaine and Hg2+. The research on LCM films is of significant value for the development of LC sensing technology and also shows great application prospects in biochemical sensing fields.

Control of Liquid Crystal Microarray Optical Signals Using a Microspectral Mode Based on Photonic Crystal Structures

Core/shell colloidal nanoparticles based multifunctional and robust photonic paper via drop-casting self-assembly for reversible mechanochromic and writing.

There is an increasing need to develop simple yet effective sensors with high sensitivity, high selectivity, rapid response, and low cost for on-site detection of UO22+ in the environment in planned or emergency situations. Herein, we develop a UO22+ responsive interpenetrating porous photonic crystal ball (IPPCB) sensor by template replication and a two-step activation method. The amidoxime group and carboxyl group in the hydrogel drive the shrinkage of the hydrogel network through the coordination with UO22+, which reduces the lattice spacing, thereby changing the structure color and shifting the reflection peak position. Therefore, we can perform a semi-quantitative analysis of UO22+ with the naked eye or a fiber spectrometer. Benefiting from the sensor's spherical symmetry and periodic interpenetrating porous structure, the sensor can provide angle-independent, fast (12 min), and sensitive (minimum detection concentration of 1 nM) detection of UO22+. Moreover, IPPCBs have high selectivity and excellent regeneration performance, which can be applied to real sample detection.

Bing Liu

Papers

Amperometric glucose biosensor based on chitosan with improved selectivity and stability

A potentiometric acetylcholinesterase biosensor based on plasma-polymerized film

Control of Liquid Crystal Microarray Optical Signals Using a Microspectral Mode Based on Photonic Crystal Structures

Core/shell colloidal nanoparticles based multifunctional and robust photonic paper via drop-casting self-assembly for reversible mechanochromic and writing.

Interpenetrating porous photonic crystal balls for rapid naked eye detection of uranyl ions.