A capacitive nanobiosensor which consists of multiwalled carbon nanotubes (MWCNTs) covered by conducting oligomer of thiophene-pyrrole derivatives was constructed and fabricated to detect the gap junction-mediated communication between living cells in a monolayer. The sensor operates on screening and spin-dependent polarization effects in nanoheterostructures which present themselves MWCNTs decorated by organometallic complexes of high-spin Fe(II) and are fabricated by a Langmuir-Blodgett (LB) technique. The nanoheterostructures were deposited on transducer, which is an interdigital electrode system covered by a dielectric layer. As the cell monolayer density increased while the cells proliferated on the sensor surface, the sensor capacity decreased until the cell monolayer was confluent. This decrement is due to a forming network of the open gap junction channels (GJCs) in accordance with an electrochemical analysis performed. The monolayer capacity increases when adding GJC inhibitor (carbenoxolone) which leads to decrease of a number of the open GJCs. The technique has been used in real-time regime to establish some principles of menadione-mediated GJC-network fine-tuning. Menadione causes Ca 2+ -dependent GJ channels opening/closing.