| The fabrication of a biosensor based on the use of the Quartz Crystal Microbalance (QCM) for glucose detection using hexokinase within a poly(acrylamide) matrix has been demonstrated. The technique combines the mass sensitivity of the QCM with the relatively large binding capacity (constant) of hexokinase for glucose. In principle, the detection scheme is a simple one. First, hexokinase is immobilized at the face of a quartz crystal. Upon exposure to glucose, binding occurs. This binding of glucose causes a subsequent mass change which is detected by the QCM. The changes in frequency which occur are too large to be solely from mass change from the binding reaction. It will be seen that the developed sensor's response is "amplified" to greater than one order of magnitude, due to viscoelastic changes within the entrapment matrix. The cause of this change in the viscoelastic properties of the acrylamide is the large conformational change which the enzyme undergoes upon binding. |
