A newly developed electrochemical cell sensor for the determination of K562 leukemia cells using 3-aminophenylboronic acid (APBA)-functionalized multiwalled carbon nanotubes (MWCNTs) films is demonstrated. The films are generated by the covalent coupling between the -NH2 groups in APBA and the COOH group in the acid oxidized MWCNTs. As a result of the sugar-specific affinity interactions, the K562 leukemia cells are firmly bound to the APBA-functionalized MWCNTs film via boronic acid groups. Compared to electropolymerized APBA films, the presence of MWCNTs not only provides abundant boronic acid domains for cell capture, their high electrical conductivity also makes the film suitable for electrochemical sensing applications. The resulting modified electrodes are tested as cell detection sensors. This work presents a promising platform for effective cell capture and constructing reusable cytosensors.