Eggenstein C, Borchardt M, Diekmann C, Gründig B, Dumschat C, Cammann K, Knoll M, Spener F
Institut für Chemo- und Biosensorik Münster, Germany.
Biosens Bioelectron. 1999 Jan 1;14(1):33-41. doi: 10.1016/s0956-5663(98)00103-1.
A potentiometric urea-sensitive biosensor using a NH4(+)-sensitive disposable electrode in double matrix membrane (DMM) technology as transducer is described. The ion-sensitive polymer matrix membrane was formed in the presence of an additional electrochemical inert filter paper matrix to improve the reproducibility in sensor production. The electrodes were prepared from one-side silver-coated filter paper, which is encapsulated for insulation by a heat-sealing film. A defined volume of the NH4(+)-sensitive polymer matrix membrane cocktail was deposited on this filter paper. To obtain the urea-biosensor a layer of urease was cast onto the ion-sensitive membrane. Poly (carbamoylsulfonate) hydrogel, produced from a hydrophilic polyurethane prepolymer blocked with bisulfite, served as immobilisation material. The disposable urea sensitive electrode was combined with a disposable Ag/AgCl reference electrode to obtain the disposable urea biosensor. The sensor responded rapidly and in a stable manner to changes in urea concentrations between 7.2 x 10(-5) and 2.1 x 10(-2)mol/l. The detection limit was 2 x 10(-5) mol/l urea and the slope in the linear range 52 mV/decade. By taking into consideration the influence of the interfering K(+)- and Na(+)-ions the sensor can be used for the determination of urea in human blood and serum samples (diluted or undiluted). A good correlation was found with the data obtained by the spectrophotometric routine method.
本文描述了一种电位型尿素敏感生物传感器，该传感器采用双基质膜（DMM）技术中的NH4(+)敏感一次性电极作为换能器。在额外的电化学惰性滤纸基质存在的情况下形成离子敏感聚合物基质膜，以提高传感器生产的重现性。电极由单面涂银滤纸制备，并用热封膜封装以实现绝缘。将一定体积的NH4(+)敏感聚合物基质膜混合液沉积在该滤纸上。为获得尿素生物传感器，在离子敏感膜上浇铸一层脲酶。由用亚硫酸氢盐封端的亲水性聚氨酯预聚物制备的聚（氨基甲酰磺酸盐）水凝胶用作固定材料。将一次性尿素敏感电极与一次性Ag/AgCl参比电极组合，得到一次性尿素生物传感器。该传感器对7.2×10(-5)至2.1×10(-2)mol/l之间的尿素浓度变化响应迅速且稳定。检测限为2×10(-5)mol/l尿素，线性范围内的斜率为52mV/十倍浓度变化。考虑到干扰性K(+)和Na(+)离子的影响，该传感器可用于测定人血和血清样品（稀释或未稀释）中的尿素。与分光光度常规方法获得的数据具有良好的相关性。
