Ag-modified SnO₂-graphitic-carbon nitride nanostructures for electrochemical sensor applications

Hydrazine is a well-known carcinogen and can cause several other adverse effects on human health such as respiratory issues, irritation of the eyes, liver and kidney problems, and dermal corrosion. An effective method is needed to detect the carcinogenic reagent like hydrazine. Tin oxide (SnO₂)-modified graphitic carbon nitride (g-C₃N₄) decorated with well-crystallized silver (Ag) nanoparticles (denoted as Ag@SO-gCN) was fabricated by a biogenic/green approach and characterized by standard techniques. A fluorine-doped tin oxide (FTO) support/substrate was coated with Ag@SO-gCN by the doctor-blade technique, and employed as the working electrode (denoted as Ag@SO-gCN/FTO) for the electrochemical detection of carcinogenic hydrazine (Hz) as a model analyte at room temperature. The dual electrochemical techniques of linear sweep voltammetry (LSV) and cyclic voltammetry (CV) were used for the detection of hydrazine (denoted as Hz). The Ag@SO-gCN/FTO sensor shows an effective current response in the detection of Hz in solutions. The concentration of Hz was very efficiently monitored using LSV and CV under different conditions. The sensor shows a low limit of detection (LOD), high sensitivity and selectivity, and good linear range. The sensitivity and LOD of this sensor using LSV are 2.01 μA μM⁻¹ cm⁻² and 0.164 ± 0.013 μM, respectively. However, the fabricated Hz sensor using CV showed a sensitivity of 2.305 μA μM⁻¹ cm⁻² and LOD of 0.143 ± 0.011 μM. This study thus provides an innovative Ag@SnO₂-g-C₃N₄-based electrochemical sensor as an effective device for the successful detection of hazardous chemicals.