Detection of Nitric Oxide from Living Cells Using Polymeric Zinc Organic Framework-Derived Zinc Oxide Composite with Conducting Polymer

Sensitive and selective detection of nitric oxide (NO) in the human body is crucial since it has the vital roles in the physiological and pathological processes. This study reports a new type of electrochemical NO biosensor based on zinc-dithiooxamide framework derived porous ZnO nanoparticles and polyterthiophene-rGO composite. By taking advantage of the synergetic effect between ZnO and poly(TTBA-rGO) (TTBA = 3′-(p-benzoic acid)-2,2′:5′,2″-terthiophene, rGO = reduced graphene oxide) nanocomposite layer, the poly(TTBA-rGO)/ZnO sensor probe displays excellent electrocatalytic activity and explores to detect NO released from normal and cancer cell lines. The ZnO is immobilized on a composite layer of poly(TTBA-rGO). The highly porous ZnO offers a high electrolyte accessible surface area and high ion–electron transport rates that efficiently catalyze the NO reduction reaction. Amperometry with the modified electrode displays highly sensitive response and wide dynamic range of 0.019–76 × 10−6m with the detection limit of 7.7 ± 0.43 × 10−9m. The sensor probe is demonstrated to detect NO released from living cells by drug stimulation. The proposed sensor provides a powerful platform for the low detection limit that is feasible for real-time analysis of NO in a biological system.