The molecular design of a PMP complex and its application in a molecular transducer for cellular NO sensing

A polymer–metal–polymer (PMP) complex was designed and synthesized as a molecular transducer for an amperometric biosensor. In the present study, the PMP complex was designed for the purpose of nitric-oxide (NO) determination in cell-culture media. It is composed of polyhistidine, copper ions, and polystyrene sulfonate. It is synthesized through coordinative self-assembly in an aqueous solution. The synthesized PMP complex is thick, and it can be spread on an electrode to form a thin membrane. NO accumulates in the PMP complex on the electrode surface, because NO forms complexes with the copper in present in the nano-cavities of the complex matrix. In that state, current response can be obtained through double-step potential application. The amount of obtained current is completely dependent on the dissolved NO concentration. The coexistence of interferents, as such as ascorbic acid, sodium nitrite, uric acid and dopamine, do not disturb the sensor response to NO. The sensor device can determine NO concentrations from 100 nM to 100 μM in cell-culture media.