Integrated Temperature Controlling Platform to Synthesize ZnO Nanoparticles and its Deposition on Al-Foil for Biosensing

Nanoparticles are considered important in numerous applications, therefore it is very imperative to have an easy, effective, and efficient nanoparticle synthesis technique. This work is aimed at the design and development of a portable thermal management device with features such as low-cost, accurate, easy-to-use, and miniaturized for nanoparticle synthesis and application. The main function of the proposed device is to control, manipulate, and monitor the cartridge heater and sensor respectively. The device is incorporated with a NodeMCU integrated with a PID temperature controller with a precision of ±2°C. A customized cartridge heater was used for heating purpose and a resistive temperature sensor acts as a feedback loop. A small petri dish of 50 mm (D), as a reservoir for the synthesis of ZnO nanoparticles, was kept at $70^{\circ }\text{C}$ for 3 h. The obtained results were subjected to FESEM and XRF characterization techniques to analyze surface morphology of nanoparticle samples which were obtained as flower-like shape and nanobars structure of 830nm in width. The synthesized ZnO nanoparticles were verified for electrocatalytic sensing of Dopamine. As a proof-of-principle, to check the Chemical Vapor Deposition of the synthesized ZnO nanomaterial on the bare aluminum foil of $18~\mu \text{m}$ at a small scale, without any complex measures or need of a controlled environment, is also provided. Further, this aluminum foil was used as a working electrode where cysteine was successfully sensed electrochemically. This portable thermal device can be used for carrying out several thermal-based reactions and analysis.