Immunosensing of Trinitrotoluene using Sol-Gel Glasses

Research in recent years has demonstrated that biological molecules such as enzymes, immunoglobulins, and other proteins can be immobilized in sol-gel derived matrices and retain their biological function. Development ofglasses with encapsulated biomolecules has opened the possibility of solid-state optical biosensors for the detection and measurement of desired analytes. In this work, we report the successful use of sol-gel silica glasses with encapsulated antibodies for the detection oftrinitrotoluene (TNT). Results show that both competitive immunoassay and displacement immunoassay are feasible using antibody-doped glasses, and these materials can detect TNT at <lppm. Moreover, the sol-gel immobilized antibodies retained the ability to discriminate between TNT and an analog, trinitrobenzene (TNB). Finally, enhanced stability was observed in the sol-gel immobilized antibodies as compared to surface immobilized antibodies.