The measurement of alkaline phosphatase at nanomolar concentration within 70 s using a disposable microelectrochemical transistor.
We report a new approach to the measurement of alkaline phosphatase concentration based on the use of a disposable poly(aniline) microelectrochemical transistor. The measurement is carried out in a two cell configuration in which the poly(aniline) microelectrochemical transistor operates in acid solution and is connected to the alkaline buffer solution containing the analyte by a salt bridge. Disposable microelectrochemical transistors were reproducibly fabricated by electrochemical deposition of poly(aniline) onto photolithographically fabricated gold microband arrays. Using these devices alkaline phosphatase was detected by employing p-aminophenyl phosphate as the substrate for the enzyme and using glucose and glucose oxidase to recycle the p-aminophenol generated upon enzyme catalysed hydrolysis of the phosphate. Recycling the p-aminophenol with glucose and glucose oxidase amplified the detection of alkaline phosphatase approximately tenfold. Using this approach we obtain linear calibration curves for alkaline phosphatase up to 5 nM within 70 s on single use devices.
Astier
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Y
School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK.
Bartlett
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PN
D000469:Alkaline Phosphatase / Q000032:analysis*; D000627:Aminophenols / Q000378:metabolism; D000814:Aniline Compounds / Q000737:chemistry; D002138:Calibration; D002384:Catalysis; D004563:Electrochemistry / Q000379:methods*; D005947:Glucose / Q000032:analysis; D005949:Glucose Oxidase / Q000032:analysis; D006046:Gold / Q000737:chemistry; D006868:Hydrolysis; D008832:Microchemistry; D011108:Polymers / Q000737:chemistry; D012680:Sensitivity and Specificity; D013997:Time Factors; D014173:Transistors, Electronic
D000627:Aminophenols; D000814:Aniline Compounds; D011108:Polymers; C416807:polyaniline; D006046:Gold; D005949:Glucose Oxidase; D000469:Alkaline Phosphatase; D005947:Glucose; C026729:4-aminophenol