Piezoelectric cell growth biosensing method using polymer-metabolic product complex interactions

A method for detecting the presence of an organism or its growth by means of a piezoelectric oscillator, comprising:

• measuring the resonant frequency of a piezoelectric oscillator having a receptor unmodified by a receptor by contacting the piezoelectric oscillator with a medium containing a metabolic product responsive polymer;
• introducing into the medium an organism capable of producing a metabolic product;
• incubating the medium to permit the production of the such that the metabolic product reacts with the metabolic product-responsive polymer to yield a polymer-metabolic product complex which deposits on the piezoelectric oscillator;
• monitoring the medium for a change in the resonant frequency of the piezoelectric oscillator caused by the deposition of the polymer metabolic product complex onto the piezoelectric oscillator such that the change in resonant frequency of the piezoelectric oscillator is used to determine the concentration, the metabolism rate, or cell growth rate of the organism.