Active mixing of immobilised enzymatic system in microfluidic chip

Parameters for sample introduction, dried reagents dissolution and mixing with sample for bienzyme system NAD(H):FMN-oxidoreductase and luciferase immobilised in microfluidic chip were successfully determined. Numerical simulations of reaction chamber geometry, flavin mononucleotide (FMN) escape from starch gel and mixing options were conducted to achieve higher sensitivity of bioluminescent reaction. Results of numerical simulations were verified experimentally. The active mixer for dried reagents was made from an electro-mechanical speaker's membrane which was connected to the input of the chip. Such a mixer provided better efficiency than a passive mixing, and it is simple enough for use in point-of-care devices with any systems based on immobilised enzymes in chips.