A new ready-to-use gel-based electrolyte for paraquat sensor

A ready-to-use electrochemical sensor offering the simplicity and portability for on-site analysis is currently in demand. Herein, we first demonstrated a new ready-to-use electrochemical sensor for on-site analysis of paraquat (PQ) using polyvinyl alcohol (PVA) gel-electrolyte. For the preparation of gel-electrolyte, hydrolyzed PVA was dissolved in DMSO: water media, allowed to cool down to room temperature before adding LiClO4, and casted onto an electrode surface. To perform the experiment, nafion-modified screen-printed graphene electrode (Nf/SPGE) was used to enhance the electrochemical signal of PQ detection using differential pulse voltammetry (DPV). Under the optimal conditions, the detection limit of 0.31 μmol L−1 was obtained. Moreover, this article reported on the comparison of PQ detection obtained from ready-to-use gel-electrolyte and liquid-electrolyte. Finally, the proposed sensor was applied for the quantitative analysis of PQ in real samples. The operation can be easily performed by directly introducing sample solution onto the sensor without any additional sample preparation. This makes a device easy to carry out for field analysis. Additionally, this newly ready-to-use electrochemical platform displays good reproducibility, high stability, simple preparation, low-cost, disposability, and portability, which makes it suitable for various applications.