Sol-gel glass as a new support matrix in immunoaffinity chromatography

A new type of immunoaffinity matrix, based on the encapsulation of antibodies in a sol-gel glass network was investigated in order to extract traces of 1-nitropyrene from water. In opposite to generally used support matrices, the sol-gel does not need an activation or derivatization step to immobilize antibodies. Also no bacteriostatic agent must be added for the storage because due to the narrow network (<100 Å) no bacteria or proteolytic enzymes can diffuse to the entrapped antibodies. Easy preparation (one-step) under mild conditions (in buffer and always at 4°C) within a short time (about 2 min) makes the sol-gel method attractive as an inexpensive immobilization technique for immunoaffinity chromatography. The sol-gel glass was used to develop an immunoadsorber for 1-nitropyrene (1-NP). No unspecific adsorption of 1-NP on the new sorbent material was found and no antibody leaching under harsh elution conditions. Traces of 1-NP were enriched with excellent recoveries and determined with on-line reduction in HPLC, followed by fluorescence detection.