Pencillin biosensor

A biosensor for measuring the concentration of penicillin in a fluid, the biosensor comprising:

• a rigid, biocompatible enclosure having an open end and a closed end, the open end being covered by a semipermeable membrane;
• a flexible diaphragm being positioned between the semipermeable membrane and the closed end;
• and a polymeric hydrogel enclosed between the semipermeable membrane and the diaphragm, the hydrogel including moieties that cause the hydrogel to change its osmotic pressure in proportion to the pH of the hydrogel;
• an amount of the enzyme immobilized in the hydrogel;
• a pressure transducers selected from the group consisting of capacitance transducers, piezoelectric transducers, and piezoresistive transducers, operatively engaged to the diaphragm.

A method for using a biosensor to measure the concentration of penicillin in a fluid, the method comprising the steps of:

• a) providing a biosensor comprising:
• a rigid enclosure having an open end and a closed end, the open end being covered by a semipermeable membrane;
• a flexible diaphragm being positioned between the semipermeable membrane and the closed end;
• and a polymeric hydrogel enclosed between the semipermeable membrane and the diaphragm, the hydrogel including moieties that cause the hydrogel to change its osmotic pressure in proportion to the pH of the hydrogel;
• an penicillinase enzyme immobilized in the hydrogel
• a means for measuring the osmotic pressure of the hydrogel, the means for measuring being associated with the diaphragm;
• and
• a means for reporting the concentration of the penicillin based on the measured osmotic pressure of the hydrogel;
• b) providing a fluid, the fluid containing an amount of the penicillin;
• c) inserting the biosensor into the fluid;
• d) allowing penicillin to diffuse into the polymeric hydrogel;
• e) allowing the penicillinase enzyme to catalyze a chemical reaction consuming the penicillin and producing penicillic acid;
• f) measuring the osmotic pressure of the hydrogel with the means for measuring;
• g) sending data regarding the osmotic pressure of the hydrogel from the means for measuring to the means for reporting;
• and
• h) reporting the concentration of the penicillin based upon the osmotic pressure of the hydrogel measured by the means for measuring.