In the present attempt a method for the immobilization of acetylcholine esterase (AChE) was developed. In this method, the enzyme was immobilized onto a ceramic cylinder support using a sol-gel-multiwall carbon nanotube (MWCNT) composite. Response surface methodology (RSM) was used for the design and analysis of immobilization experiments. Quadratic mathematical model equations were derived for the prediction of enzyme activity. Then the effects on enzyme activity at 30, 40 and 50 min after process initiation of varying each of two parameters over five levels were investigated. These parameters were the AChE:MWCNT ratio (X(1)), and AChE-MWCNT:sol-gel ratio (X(2)). The optimum values of X(1) and X(2) for the immobilization of AChE on ceramic packing were found to be 1.07 and 0.43, respectively. Using these Optimum parameters it was shown that enzyme immobilization with MWCNTs and sot-gel was more effective than immobilization with sol-gel or graphite and sol-gel. Scanning electron microscopic (SEM) images revealed a porous surface comprised of MWCNT-AChE encapsulated in sol-gel. Furthermore, the system was highly reproducible with standard deviations after three successive assays of 1.88%, 2.11% and 2.13% at 30, 40 and 50 min after process initiation, respectively. (C) 2009 Elsevier Ltd. All rights reserved.