EFFECT OF STRUCTURE OF FUNCTIONAL POLYMER ACTIVE MATERIALS ON PROPERTIES OF GADOLINIUM ION SELECTIVE ELECTRODE

In this paper,the functional polymeric active materials were prepared by the grafting copolymerization and their structure and properties were studied.The results show that the structure and properties of these ac- tive materials have the relative large effects on the properties of gadolinium ion selective electrodes.

Flexible and Stretchable Electrodes for In Vivo Electrophysiological and Electrochemical Monitoring

In vivo monitoring of bioelectrical and biochemical signals with implanted electrodes has received great interest over the past decades.However,this faces huge challenges because of the severe mechanical mismatch between conventional rigid electrodes and soft biological tissues.In recent years,the emergence of flexible and stretchable electrodes offers seamless and conformable biological-electronic interfaces and has demonstrated significant advantages for in vivo electrochemical and electrophysiological monitoring.This review first summarizes the strategies for electrode fabrication from the point of substrate and conductive materials.Next,recent progress in electrode functionalization for improved performance is presented.Then,the advances of flexible and stretchable electrodes in exploring bioelectrical and biochemical signals are introduced.Finally,we present some challenges and perspectives ranging from electrode fabrication to application.

Electrochemical Study and Application on Shikonin at Poly（diallyldimethylammonium chloride） Functionalized Graphene Sheets Modified Glass Carbon Electrode

The electrochemical behaviors of shikonin at a poly（diallyldimethylammonium chloride） functionalized graphene sheets modified glass carbon electrode（PDDA-GS/GCE） have been investigated. Shikonin could exhibit a pair of well-defined redox peaks at the PDDA-GS/GCE located at 0.681 V（Epa） and 0.662 V（Epc）[vs. saturated calo- mel electrode（SCE）] in 0.1 mol/L phosphate buffer solution（pH=2.0） with a peak-to-peak separation of about 20 mV, revealing a fast electron-transfer process. Moreover, the current response was remarkably increased at PDDA- GS/GCE compared with that at the bare GCE. The electrochemical behaviors of shikonin at the modified electrode were investigated. And the results indicate that the reaction involves the transfer of two electrons, accompanied by two protons and the electrochemical process is a diffusional-controlled electrode process. The electrochemical para- meters of shikonin at the modified electrode, the electron-transfer coefficient（a）, the electron-transfer number（n） and the electrode reaction rate constant（ks） were calculated to be as 0.53, 2.18 and 3.6 s^-1, respectively. Under the optimal conditions, the peak current of differential pulse voltammetry（DPV） increased linearly with the shikonin concentra- tion in a range from 9A72×10^-8 mol/L to 3,789×10^-6 mol/L with a detection limit of 3,157× 10^-8 mol/L. The linear regression equation was Ip=O.7366c＋0.7855（R=0.9978; lp： 10-7 A, c： 10-8 mol/L）. In addition, the modified glass carbon electrode also exhibited good stability, selectivity and acceptable reproducibility that could be used for the sensitive, simple and rapid determination of shikonin in real samples. Therefore, the present work offers a new way to broaden the analytical application of graphene in pharmaceutical analysis.

Molecular-scale electronics： From device fabrication to functionality

By wiring molecules into circuits, ＂molecular electronics＂ aims at studying electronic properties of single molecules and their ensembles, on this basis exploiting their intrinsic functionalities, and eventually applying them as building blocks of electronic components for future electronic devices. Herein, fabricating reliable solid-state molecular devices and developing synthetic molecules endowed with desirable electronic properties, have been two major tasks since the dawn of molecular electronics. This review focuses on recent advances and efforts regarding the main challenges in this field, highlighting fabrication of nanogap electrodes for single-molecule junctions, and self-assembled-monolayers （SAMs） for functional devices. The prospect of molecular-scale electronics is also discussed.