Superior electrocatalyst based on mesoporous silica nanoparticles/carbon nanotubes modified by platinum-copper bimetallic nanoparticles for amperometric detection of hydrazine

Hydrazine is a volatile, water-soluble molecule with strong reducing ability that is widely used in various industrial and pharmaceutical fields. It is known as a combination of carcinogens and neurotoxins that have harmful effects on the liver, brain, nervous system and DNA and also cause blood disorders. Therefore, developing a sensitive, accurate, simple and fast way to measure hydrazine concentration is very important. Here, a novel and efficient sensor for the determination of hydrazine at trace level is introduced by modifying mesoporous silica nanoparticles (MSNPs)/multi-walled carbon nanotubes dispersed in carbon paste electrode with PtCu nanoparticles (PtCu NPs/MSNPs/CNTs/CPE). SBA-15 NPs as one of the MSNPs are stable matrix for bimetallic NPs which prevent their accumulation and provide conditions for low loading of catalyst due to its unique structure. For this purpose, MSNPs was firstly synthesized from stem sweep ash (SSA) as raw material. The suggested sensor indicated favorable analytical performance in 0.1 M phosphate buffer solution (PBS, pH = 7.4) with a low limit of detection (S/N = 3.3) of 0.09 μM in the wide linear range of 6 μM−17.24 mM, high sensitivity of 47.18 μA mM−1, rapid response time of ∼3 s and high repeatability/reproducibility. The analytical performance of PtCu NPs/MSNPs/CNTs/CPE originates from the presence of more available bimetallic active sites and the synergistic effect of MWCNTs with high electrical conductivity. In the presence of some usual interferences, the sensor indicated high selectivity for hydrazine detection. The practical application of PtCu NPs/MSNPs/CNTs/CPE in real samples was also evaluated. The results showed that the MSNPs with large porosity and high surface area are efficient substrate for catalyst formation and cause to fabrication of sensor with excellent accuracy, precision, and recovery for the determination of hydrazine.