The influence of B-site cation in LaBO3 (B = Fe, Co, Ni) perovskites on the nanomolar sensing of neurotransmitters

LaNiO3, LaFeO3 and LaCoO3 perovskites were synthesised by solution combustion method. The phase formation, purity, structure, thermal stability, surface features, morphology, defect formation of the synthesised materials were studied by Powder X-ray diffraction, infrared spectroscopy, thermogravimetry, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopies. Sensors were developed using these perovskite materials by modifying the carbon paste electrode. On modification, electrochemical surface area was considerably increased and charge transfer resistance of the modified electrodes were significantly lower. The modified electrodes had high current response which enabled the nanomolar sensing of neurotransmitters. Different electrochemical parameters of modified electrodes showed significant improvements towards oxidation/reduction of dopamine (DA), serotonin (ST), acetaminophen (AAP) and tyrosine (TYR). Perovskites modified carbon paste electrode (LNO MCPE) exhibited a wide linear range, high sensitivity and excellent selectivity. This enabled the simultaneous detection and quantification of four key molecules. The LOD (limit of detection) values were 9, 14, 35, and 56 nM respectively for DA, ST, AAP, and TYR. The interference studies, stability and real sample analysis further proved the practical usage of the developed sensor.

Automated summary

LaNiO3, LaFeO3, and LaCoO3 perovskites were synthesized using solution combustion method, and sensors were developed for nanomolar sensing of neurotransmitters. The modified carbon paste electrodes showed high sensitivity, selectivity, and wide linear range for the simultaneous detection and quantification of dopamine, serotonin, acetaminophen, and tyrosine.