Porosity tuned NiO nanocrystallites by solution combustion synthesis for the development of a voltammetric sensor for dopamine

Nickel oxide (NiO) nanocrystallites of porous structure were synthesised by solution combustion method. The influence of F/O ratio on the structural, morphological and electrochemical parameters was investigated. The sample synthesized at F/O ratio 0.4 had a crystallite size of 5 nm. This sample possesses greater surface area and high porosity whereas the sample synthesized at F/O 0.2 was not porous and had lower surface area. Porous NiO was used to modify the carbon paste electrode for the selective detection of dopamine (DA) in the presence of a lot of excess ascorbic acid and uric acid. Sodium dodecyl sulphate (SDS) casting onto the NiO modified electrode improves the performance towards DA. NiO/SDS/MCPE electrode is completely insensitive to ascorbic acid signals below 1.0 × 10⁻³ M and enables the accurate quantification of DA in presence of 1000 fold excess of UA (uric acid). The fabricated electrode shows good reproducibility, stability and linear dynamic range of 0.3–300 µM.