Nickel hydroxide nanoflowers (f-Ni(OH) 2 ) were synthesized in present work. The crystal structure of as-prepared sample is β-Ni(OH) 2 phase (JCPDS # 14-0117). A nano composite film was fabricated by dispersing nano scale f-Ni(OH) 2 and carbon nanotubes (CNTs) into Nafion solution. The electrocatalytic oxidation of glucose in alkaline medium on the f-Ni(OH) 2 -CNT-Nafion composite (fNCN) modified glass carbon electrode (GCE) had been investigated. The prepared f-Ni(OH) 2 -CNT-Nafion / Glass Carbon electrode (fNCN/GCE) glucose sensor could produce large electrocatalytic oxidation current in glucose solution when the applied potential exceeds 0.32 V vs. SCE, which is much lower than the similar sensor based on Ni(OH) 2 nanosheets (s-Ni(OH) 2 ) and is comparable to α-Ni(OH) 2 sensor. Amperometric measurements were done with different concentrations of glucose. The fNCN/GCE glucose sensor has high sensitivity and low detection limit at a potential of 0.45 V (vs. SCE). It showed a detection limit of 0.5 μM (S/N = 3) and a sensitivity of 16.85 μA mM −1 (238.5 μA mM −1 cm −2 ) with a linear range from 0.1 to 1.1 mM. The K m derived from Lineweaver-Burk equation is evaluated to be 4.25 mM, which is much lower than enzymatic glucose biosensor.Diabetes is a group of metabolic diseases in which a person has high blood sugar than the normal range (4.4-6.6 mM). The development of glucose sensing methods is of considerable importance for the diagnosis of some diabetes. Much effort has been made to develop glucose sensors because of the high practical relevance of glucose determinations. 1-5 Electrochemical glucose biosensors, especially amperometric biosensors, have been widely used because of its simple, accurate and fast analytical process. Good selectivity and high sensitivity for glucose detection have been achieved by glucose enzymatic biosensors due to the specificity of glucose oxidase. 6,7 However, the insufficient long-term stability and unsatisfactory reproducibility originated from the nature of the enzymes remains as problems for real sensor applications. 8 Therefore, nonenzymatic glucose sensors which means the direct electrochemical oxidation of glucose without enzyme have received continuous interest in the past decade. [9][10][11][12] The electrocatalytic activity of electrode materials is a key factor that affects both the sensitivity and selectivity of glucose detection. Higher performance for glucose detection has been obtained by using nanomaterials such as Pt, 13,14 Au,8,9 Cu/CuO,15,16 Pt/Pb nanoparticles, 11,17 and carbon nanotube. 18 However, the nonenzymatic direct oxidation of glucose based on the mentioned electrodes has a key problem, which is the low sensitivity due to the sluggish kinetics of glucose electro-oxidation. 8 Some researches show that nonenzymatic electro-oxidation of glucose is greatly enhanced on Ni based electrode compared to the other electrodes. 19,20 Several kinds of electrodes contained Ni, NiO or Ni(OH) 2 nano-composite had been reported, which showed highly sensitive, selective...

A nano composite film was fabricated by dispersing nano scale Ni(OH) 2 and carbon nanotubes (CNTs) into polyvinylidene fluoride (PVDF). The mophorlogy of the film was examined by scanning electron microscopy (SEM). The electrocatalytic oxidation of glucose in alkaline medium on the Ni(OH) 2 -CNT-PVDF (NCP) composite modified glass carbon electrode had been investigated. The stability of the composite is confirmed by cyclic voltammetry measurements in sodium hydroxide solution (0.50 M, scan rate 100 mV s −1 ). The NCP composite film maintains the electrocatalytic activity of the nano scale Ni(OH) 2 and is used to fabricate a nonenzymatic biosensor for electrochemical detection of glucose. Amperometric measurements were done with different concentrations of glucose. The NCP glucose sensor has good anti-interference performance toward maltose, fructose, urea, and ascorbic acid. It has wide concentration ranges to glucose. It shows a detection limit of 0.023 mM (S/N = 3) with a wide linear range from 0.25 to 39.26 mM, which is comparable with commercial glucose test strip. In real serum sample, it has a RSD of 2.5%.

Poly-diallyl-dimethyl-ammonium chloride (PDDA) solution was used to disperse carbon nanotubes (CNTs) to form a stable PDDACNTs aqueous dispersion. The negatively charged glucose oxidase (GOx) and positively charged PDDA-CNTs composite were used to prepare multilayer biosensing films on glassy carbon electrodes (GCE) via layer-by-layer (LBL) self-assembly technique. The optimum number of layers on GCE was 4. A mixture of 3-dimethyl (methacryloyloxyethyl) ammonium propane sulfonate (DMAPS) and Graphene (GR) was dropped on the multilayer films to prepare a bacteriostatic glucose biosensor. The results show that CNTs could evenly disperse in the PDDA films and the multilayer PDDA-CNTs films can significantly improve the catalytic current response toward glucose (Glu). The biosensor could detect glucose linearly from 16.5 to 214. Electrochemical biosensors which utilize immobilized oxidase [1][2][3][4][5][6] or metal/metal oxide 7-10 to catalyze the oxidation of target analyte, could respond to the changes of concentration of the analyte, and output electrical signal with some disciplines. It can be used to determine biological, clinical, or environmental substances.11-13 Many works have been carried out to achieve high biosensing performance. 14-17However, less research has been done about the bacteriostatic electrochemical glucose biosensor.Antimicrobial or bacteriostatic material has been widely used in industries such as textile, food fermentation and medical device industry. 18,19 In the process of bio-fermentation, the detection of various biochemical parameters (biomass, cell activity, substrate, nutrition, products and metabolites) forms the basis of controlling process of the fermentation. 20 The growth rate of micro-organism can be monitored by the consumption of glucose. Consequently, the abnormal phenomenon of fermentation process can be forecasted by the timely detection of glucose.21 However, bacterium can be easily adsorbed on the surface of the glucose sensors to form a bio-film. The bio-film can block the substrate close to the electrode, and the accuracy of the detection can be affected. 22 In these cases, it is especially necessary to use antimicrobial or bacteriostatic glucose biosensors. But there are very few studies reporting the antimicrobial or bacteriostatic electrochemical glucose biosensor. In this paper, a bacteriostatic film is built on GCE via layer-by-layer (LbL) self-assembly method and used to construct a glucose sensor.It is generally known that chemical compounds contain quaternized ammonium groups and that zwitterionic sulfopropylbetaine shows bacteriostatic or antimicrobial properties, 23 besides the zwitterionic materials show outstanding protein resistance performance. 24,25 A typical sulfobetaine, 3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate (DMAPS) (Scheme 1), which contains a sulfonate group and a quarternized ammonium separated by an alkyl spacer, has outstanding antimicrobial properties.Layer-by-layer (LbL) self-assembly method is a useful and versatile tech...