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We describe a low-cost and disposable indium-tin-oxide (ITO) chip modified with multi-walled carbon nanotubes (MWNTs) and covered with filter paper. It is capable of sensitively detecting dihydronicotinamide adenine dinucleotide (NADH). The response to NADH occurs at a relatively low potential (0.42 V vs. Ag/AgCl) and is not interfered by ascorbic acid. The influence of electrode area and the amount of assembled MWNTs on the analytical signals were studied. Under optimized experimental conditions, the amperometric response to NADH is linear in the 0.25 μM to 0.1 mM concentration range, and the detection limit is 50 nM. Chronoamperometry was performed in order to study the electron transfer kinetics of NADH, and average diffusion coefficients and apparent rate constants were determined. In our perception, this approach provides an effective way to quantify NADH and therefore has a large potential in the field of NADH-related diagnostics and enzymology. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]