Study on Novel Glucose-Responsive Materials for GOX-Free Glucose Sensors

Zhejiang University, Professor Li Wang

The University of Leeds, Professor Long Lin

The University of York, Dr. Steven D. Johnson

   

Diabetes is a disorder of glucose regulation. It is a chronic disease that has a significant, negative impact on the health of a large proportion of population. The worldwide prevalence of diabetes is predicted to double to 366 million by 2030 from 171 million in 2000. It is the third largest cause of death following cancer and angiocardiopathy. Reliable sensing of glucose concentration is crucial for diagnosis and treatment of diabetes. Among various platforms, electrochemical (EC) methods have high sensitivity and fast response rate. However, glucose oxidase (GOX) has to be involved in EC sensors to recognize glucose via a redox reaction. A number of inherent problems are associated with the GOX-based sensors, such as inefficiency of the electron transfer between GOX active site and electrode surface. Particularly, as a biological enzyme, the activity of GOX varies depending on temperature, moisture and chemical environment and denatures during the storage. These problems can be resolved by exploring a GOX-free direct EC sensing mechanism and yet little has been reported in this area. The aim of this WUN project is to develop novel glucose-responsive materials for GOX-free glucose sensors for glucose detection of diabetes.

 

The project carried out by an interdisciplinary joint research team from Zhejiang University, University of Leeds and University of York. The researchers of the joint team are currently exploring novel glucose-responsive materials for GOX-free glucose sensors which will be more sensitive and stable. When phenylboronic acid (PBA) fragment is conjugated with redox ferrocene group, PBA/glucose interactions will generate detectable electrochemical (EC) signals due to electron communication between the two components. This stimulated EC signal variation does not rely on GOX-catalyzed redox reactions and can be used for GOX-free glucose EC sensors. A series of novel glucose-responsive PBA based compounds and polymers have been designed and synthesized. The influences of PBA content, glucose concentration, pH and temperature of the surrounding on the glucose-responsive properties of the resultant materials have been investigated. Glucose responsive EC signals of all designed conjugates were investigated and compared in order to understand structure vs function relationship. In next step, promising candidates will be identified and integrated into sensors for blood sample and interstitial fluid test. Electrochemistry study will also provide feedbacks for rational materials design in an attempt to meet requirements for clinical applications. A joint research workshop has been hosted and several joint publications and competitive funding application are going forward. The success of this project will overcome several drawbacks associated GOX-mediated sensors and offers new opportunities for the development of a new generation of reliable, highly sensitive glucose sensors.