Ion-sensitive field effect transisors (ISFETs) have found groiwing interest in the rapidly developing field of biosensors. The prenciples, application and new developing techniques of ISFET-based biosensors are reviewed.

Meso-scale metal phthalocyanice (MPc, M=Cu, Ni, Mn, or Co)-Fe3O4 nanocomposties for EMR fluids have been prepared and well characterized. The results indicate that there exists chemical bonding between MPc and Fe3O4 nanoparitcles, and their strength of chempared to Fe2O4 nanoparticles, MPc-Fe2O4 nanocomposites have superior ability to nnti-oxidation and thermal stability, and show almost the same saturation magnetic strength, but much less coercive force, All MPc-Fe3O4 nanocompostites have irregular spherical shape with D of 0.2～0.4μm. The EMR fiulid containing MPc-Fe3O4 nanocomposites in chlorinated paraffin oil have excellent stability and redispersibity. They show reversible significant field-induced shear stress. which increase linearly with the incement of electric field strength (E) or H and which are different for MPc-Fe3O4 nanocomposites containing various metal elements, when E or H is applied respectively. Furthermore, field-induced shear stress shows obvious synergetic effect when E and H are applied simultanceously.

Low-density cobalt-phthalocyanine (Co-Pc)/Fe nanocomposite particale with both adjustable electric and magnetic properties were synthesized using one-step thermolysis. The nanocomposite particales wrer fully characterized by fourier transform infrared spectroscopy, X-ray diffraction analysis, scanning electron The magnetic hysteresis loop and microwave electromagnetic parameters of the nanocomposite particles were measured. The magenetorheologyical (MR) properties of the MRsuspensions based on the nanoncomposte particaled dispersed in methyl silicone oil were investiated as functions of weigth percent of particles, nanocomposite consisted of micrometer-sized regular spheroids with hundreds of thousands of Co-Pc-coated α-Fe nanoparticles on the inside and Co-Pc layers on the surface of the spheroids. It showed good characteristics of antioxidation and high magnetic susceptibility. For nanocomposites containing 82.7wt% Fe, woth omcreasomg, ocrpwave freqiemcu. the complex permeability (Ur) occurred. In comparison with conventional carbonyl iron powders, the density of the nanocomposite particles was much lower, and εrdecreased signiflaantly while μr hardly changed. magnetic field induced shear stress of the MR suspension based on nanocomposites with 89.7wt% Fe was basically independent of T and γ but increased abruptly with increasing H. With increasing T. response time of the MR suspension to an external masgnetic field seemed to decrease. The results suggested that the synthesized Co-Pc/Fe nanocomposite particles with different compositions could be utilized as an excellent microwave absorber and as dispersed particles of high-performance MR suspensions.

Electrochemical impedance spectroscopy (EIS)is a sensitive indicator of a wide variety of chemical and physical properties. Au increasing trend towards the develoment of impedimettric biosensors is being curremtly observed. Impedimetric techniques have been performed to characterixe the fabrication of the biosensors and to monitor the catalyzed reactions of enzymes or the biomolecula recognition events of specific binding proteins, lectins, reeptors, nucleic acids, whole cells, antibodies or antibody-related substances. However, little attention has beenpaid to reviewing this interesting research area. Herein, impedimetric biosensors are reviewed and many novel designs are discussed.

The aim of this study was to develop a rapid method to measure α-fetoprotein (AFP) in human serum by use of one-step sandwich enyme-linked immunosorbent assay (ELISA)-BASED immunobiosensor with disposable scree-printed carbon electrod technology. Prussian blue (PB) was de[psote disomg cyclic volatmmetry (CV) on the surface of electrode to catlalyze H2O2 from the reaction of gluecose oxidease. It took only about 30min to complete. the whole experimental procedure trough flow injection ajalysis (FIA) A detction range obtained is the range from 5 to 500ng/ml AFP. This deterction ceems to be quick, reliable and practoca.