A Langmuir-Blodgett (LB) film consisting of glutaraldehyde as the binding site for enzyme molecule, an amphiphilic N-alkyl-bis(thiophene) carbazole (BTC7) as the additional electron mediator, and 22-tricosenoic acid (TA) as the matrix for these molecules were deposited on a hydrophilic substrate. Laccase was then covalently immobilized on the film via glutaraldehyde (GA). The sensitivity of this sensor was about twice as high as that of laccase sensor prepared with the same LB film as above but without the bis(thiophene)carbazole derivative. The laccase LB film exhibited enzyme activity. (c) 2007 Elsevier B.V. All rights reserved.