DETECTION OF SULFAMETHOXAZOLE USING PIEZOQUARTZ IMMUNOSENSOR Russian patent published in 2006 - IPC G01N33/53 

FIELD: sulfamethoxazole detection in foodstuffs (eggs, poultry and animal meet, milk and milky products), in pharmaceutical compositions, and environmental objects (soil, industrial waste and natural water).

SUBSTANCE: piezoquartz immunosensor is fixed in 15-20 ml flow-through cell in such a manner that it contacts with tested solution in one side only. Volume of obtained mixture is adjusted with phosphate buffer solution to 1 ml and mixture is conditioned at 20°C for 15 min until reaction is finished. Before measurements phosphate buffer solution (pH 7.2) is passed through cell to stabilize the sensor signal. Then in buffer solution flow probe (0.2 ml) is introduced. As a result sensor vibration frequency in reduced due to formation of sulfamethoxazole-protein conjugate and antibody complex on electrode surface. Antibodies are introduced into analyzed sample in amount corresponding to 50 % bonding thereof to sulfamethoxazole-protein conjugate. Receptor coating is regenerated with 0.4 mM potassium thiocyanate solution.

EFFECT: decreased sulfamethoxazole detection limit, increased selectivity in complex samples.

1 tbl