Amperometric enzyme electrodes for lactate and glucose determinations in highly diluted and undiluted media

A Simple FIA-System for Simultaneous Measurements of Glucose and Lactate with Amperometric Detection

“…Normal glucose concentration level in blood serum is in the range of 4.2 to 6.1 mM, whereas a derailed mechanism may cause an increase of this level up to 40 mM [22]. On the other hand normal blood lactate value is below 2.7 mM whereas extreme exercise and metabolic stress may cause an increase in lactate concentration up to 30 mM.…”

“…The main body of the relevant literature considered either glucose or lactate as a single targeted analyte [10, 15±18], nevertheless, several other articles considered glucose and lactate together as two targeted analytes [19±33]. The later articles presented different prospectives including i) development of two independent enzyme-based biosensors for glucose and lactate as two models for a given new principle [21,22,25,28], ii) integration of both glucose and lactate biosensors in single chips which were used mainly in the batch mode [24,27,29], iii) microdialysis system coupled with a commercial glucose and lactate analyzer [26], iv) microdialysis system with on-line monitoring using two respective amperometric biosensors [32,33], and v)¯ow injection system for glucose and lactate determination based on immobilized enzyme reactors (IERs) coupled with either a modi®ed graphite electrode [23], or commercial enzymatic membranes and a commercial analyzer with amperometric detection [19], or ®ber optic detection [20].…”

O 2 -sensitive L-Lactat-Biosensoren mit Enzymmembranen auf der Basis von L-Lactat-2-monooxygenase und L-Lactat-Oxidase im elektroanalytischen Vergleich - An Electro-analytical Comparison of O2-sensitive L-lactate Biosensors. Using Enzyme Membranes on the Basis of L-lactate-2-monooxygenase and L-lactate oxidase

“…Da L-Lactat-Oxidase (LOD) und L-Lactat-2-monooxygenase (LMOG) gleichermaßen ihr Substrat L-Lactat unter Sauerstoffverbrauch umsetzen, ist die reaktandenbezogene Messung des Analyten in beiden Fällen nach den Gleichungen (1) und (7) über den Sauerstoffverbrauch mittels O 2 -Detektoren ausführbar [14][15][16]; bei einer elektrochemischen Erfassung der Reaktionsprodukte können nach Gleichung (1) der H 2 O 2 -Sensor [13] und nach Gleichung (7) die gassensitive CO 2 -Elektrode als Detektoren herangezogen werden.…”

Biosensor Microsystems

“…At present, nearly all of the cited amperometric microelectronic sensors intended for long-term application are not able to work well in undiluted blood, and even few conventional macroscopic sensor systems are able to measure glucose and lactate concentrations in undiluted media for an extended period [70,71].…”

“…To overcome the described problems, apart from the dilution method the solution is to utilize complex membrane systems [70,71,74]. In addition, problems have to be overcome concerning immobilization of biological substances and to establish proper diffusion limitation.…”