Highly sensitive formaldehyde detection using well-aligned zinc oxide nanosheets synthesized by chemical bath deposition technique

Detection of formaldehyde is very important in terms of life protection, as it can cause serious injury to eyes, skin, mouth and gastrointestinal function if indirectly inhaled. Researchers are therefore putting effort into developing novel and sensitive devices. In this work, we have fabricated an electro-chemical sensor in the form of a field effect transistor (FET) to detect formaldehyde over a wide range (10 nM to 1 mM). For this, ZnO nanosheets (NS) were first synthesized by hydrothermal method with in-situ deposition on cleaned SiO ₂ /Si (100) substrate. The synthesized materials were characterized for morphology and purity and surface area (31.718 m ² /g). The developed device was tested for formaldehyde detection at room temperature that resulted in a linear (96%) and reproducible response with concentration, sensitivity value of 0.27 mA/M/cm ² with an error of ±2% and limit of detection (LOD) as 210 nM.