Stretchable sensor based on NiO-Ni(OH)₂ and single-walled carbon nanotubes for in situ and real-time monitoring of dopamine release from cells

As the most abundant catecholamine neurotransmitter in the human brain, dopamine directly facilitates intercellular communication and is closely related to multiple functions of the central nervous system. Here, a flexible and stretchable electrochemical sensor based on NiO-Ni(OH)2 and single-walled carbon nanotubes (SWCNTs) on flexible poly-dimethylsiloxane (PDMS) substrate was fabricated for the sensitive quantification of dopamine released from different cells. The developed NiO-Ni(OH)2/SWCNTs/PDMS film exhibited excellent selectivity and sensitivity to dopamine with a wide linear range from 50 nM to 288 mu M and a low detection limit of 12 nM (S/N = 3). The prepared sensor is highly biocompatible, where living cells can grow and proliferate directly on the electrode surface with strong adhesion, allowing for the in situ and real-time tracking dopamine secretion from cells. This work indicated that the flexible NiO-Ni(OH)2/SWCNTs/PDMS can serve as an effective sensing platform for monitoring cellular signal molecules released from living cells during mechanical deformation.