Title of the invention: A process to characterize biochemical reaction using sensor instrumentation based on capacitance and conductance change

Date of filing                        : 18/10/2010
    Application No                     : 3064/CHE/2010
    Name of the applicant          : REGISTRAR, ANNA UNIVERSITY CHENNAI
    Name of inventor                 : Mr. Kumar et al

Abstract:

The main objective of the present invention is to design a process based on change in charge status in terms of capacitance combined with the electrochemical method to determine the kinetics of prismatic systems without adding any additional reagents. The measurement can be performed in an electrochemical cell as a transducer in biosensors.

The invention involves the addition of basic enzymatic assay compounds into the electrochemical curette. This includes the low ionic strength buffer and substrate solution. Then the enzyme preparation is added and the change in capacitance and conductance is measured. The slope gives directly the rate of change in capacitance proportional to the progress of the reaction. This process is easily adaptable for automated instrumentation.

To validate the capacitance and conductance based process with the enzyme kinetics, active and inactive preparations of as the enzymes, unease, alkaline phosphates, pyrophosphates, glucose oxidize and esterase were studied and the results of their respective optical methods (spectrophotometer assays) were compared with the capacitance method and found to be matching. For example, hydrolysis of the uncharged compound, urea, releases carbonate and ammonium ions into the electrochemical cell, which results in the increase of original capacitance. Rate of change (increase in this case) is the measure of progress of the reaction. When catalyzed by an enzyme like unease, the rates of capacitance change. As measured by a sensitive capacitance meter capable of measuring nana and Pico farads, gives a direct measure of enzymatic catalysis