Novel Planar Chip Biosensors for Potentiometric Immunoassay of Acid Phosphatase Activity Based on the Use of Ion Association Complexes as Novel Electroactive Materials

摘要

The construction and general performance characteristics of two poly (vinyl chloride) matrix chemicalsensors for -naphthyl acid phosphate (1-NAP) substrate were described. These sensors were based onthe use of ion association complexes of (1-NAP) with cetylpyridinium chloride (CP) [sensor 1] and2+ iron (II) - 4,7-bathophenanthroline [Fe(bphen)3] [sensor 2] as novel electroactive materials dispersedin o-nitrophenyloctyl ether (o-NPOE) plasticizer for ionometric sensor controls. The sensingmembrane (3 x 5 mm) is immobilized on a wafer polyimide chip (size 13.5 x 3.5 mm) to offer a planarminiaturized design. The sensors displayed good selectivity and stability and demonstrates a near- -2 -5 -2 -6 Nernstian response for 1-NAP over the concentration range 1.0x10 - 1.0x10 and 1.0x10 - 9.0x10-1 -1 -6 mol L with an anionic slope of -57.30.9 and -56.61.1 mV decade and a detection limit of 9x10-6 -1 and 8x10 mol L over the pH range 2.8 5.5 for sensors 1 and 2, respectively. The sensors were usedto follow up the decrease of a fixed concentration of 1-NAP substrate as a function of acid phosphataseenzyme activity under optimized conditions of pH and temperature. A linear relationship between the-1 initial rate of 1-NAP substrate hydrolysis and enzyme activity hold 0.01- 4.3 IU L of ACP enzyme.The sensors were used for the determination of ACP enzyme activities in biological fluids of somepatients suffering from prostatic cancer. The results obtained agree fairly well with data obtained bythe standard spectrophotometric methods.