Many antioxidants can be electrochemically oxidized using graphite-based electrodes; nevertheless problems arise due to the strong adsorption of redox species at the sensing area. We have demonstrated that boron doped diamond (BDD) electrodes do not show this property, which can be exploited for the design of a new amperometric sensor for the quantification of antioxidants as “total antioxidant capacity” (AOC). As reference substances hydroquinone (HQ) and 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox) were studied in more detail. The supporting electrolyte was a phosphate buffer solution (PBS, 0.1 mol/L, pH 7.0). The limits of detection (LOD) were 1.5 mg/L and 2.5 mg/L for HQ and Trolox, respectively. The repeatability was 3 % RSD for concentration of 200 mg/L HQ. The method could be applied for the determination of AOC in different berry samples, such as strawberry, blueberry, grape and bramble. A comparison with a standard photometric assay showed good correlation between both methods. The BDD sensor features good reproducibility without fatiguing over at least two months of operation
130 million people in Western Europe and the USA suffer from chronic cardiac degeneration or kidney insufficiency. The medical treatment requires a routine medical examination accompanied by laboratory blood analyses. This is cost-intensive for the health care system and also time consuming for the patients. This paper presents an economical, wireless sensor node solution in terms of an intelligent near field communication (NFC) potassium measurement strip (NPMS) usable in a home environment. The NPMS comprises two different electrochemical sensors for the acquisition of two parameters in capillary blood and an autonomous sense and identification grain (ASIG) for the electrical analysis, communication, and data transfer. The ASIG is equipped with an integrated amperometric and potentiostatic functionality, radio frequency identification (RFID) interface for high frequency (HF)/NFC, and has been designed using a 130 nm CMOS standard process. It facilitates the implementation of two different measurement techniques, which are necessary for the accurate determination of the potassium concentration in capillary blood, whereby the occurrence of hemolysis can be detected. This NPMS impresses with its large scale integration and is solely powered by the NFC reader device.Keywords: NFC; amperometry; potentiometry; CMOS Intelligenter NFC-Kalium-Messstreifen mit Hämolysekontrolle in Kapillarblut. Mess-und Identifikations-Chip (ASIG)
Millionen Menschen in Westeuropa und den USA leider an chronischer Herz-oder Niereninsuffizienz. Die Behandlung erfordert eine regelmäßige medizinische Untersuchung, welche mit Laboranalysen des Blutes einhergeht. Dies ist kostenintensiv für das Gesundheitswesen und auch zeitaufwendig für den Patienten. Dieser Beitrag präsentiert eine ökonomische, drahtlose Sensorknotenlösung in Form eines intelligenten NFC-Kalium-Messstreifens (NPMS) für den Heimgebrauch. Der NPMS enthält zwei verschiedene elektrochemische Sensoren für die Erfassung zweier Parameter im Kapillarblut und einen autonomen
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