The detection of water pollutants employing organic field-effect transistor (OFET) sensor requires a stable performance in an aqueous media. It is an essential condition of any sensor to present reliable measurements. Some organic-conducting polymers deteriorate almost immediately in the presence of an aqueous medium. However, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has proven its stability in both air and aqueous mediums. Nevertheless, due to inadequate structural and chemical properties of the PEDOT:PSS, it persists major obstacles and inhibits its performance in practical applications. These shortcomings can be overcome with the combination of carbon nanomaterials. Therefore, the present study deals with the effect of inclusion of reduced graphene oxide (rGO) into PEDOT:PSS, and it resulted in the enhancement of structural, morphological, and electrical properties of the PEDOT:PSS/rGO nanocomposite. The organic field-effect transistor (OFET) was fabricated with PEDOT:PSS/rGO nanocomposite to detect heavy-metal ions. This makes a highly sensitive and selective sensor platform for detecting Hg²⁺ in the linear concentration range of 1–60 nM. The presented OFET sensor manifests high sensitivity and selectivity to Hg²⁺ with a low detection limit of 2.4 nM. The variety of metal ions tested, i.e., Hg²⁺, Cd²⁺, Pb²⁺, Cu²⁺, Zn²⁺, Na⁺, and Fe³⁺, to investigate the selectivity. The sensor exhibits stable performance in an aqueous medium for the detection of Hg²⁺ in the presence of DI water. Moreover, the OFET sensor responded within 2–3 s after incubation of Hg²⁺ ions’ solution.

使用有机场效应晶体管（OFET）传感器检测水污染物需要在水性介质中保持稳定的性能。提供可靠的测量是任何传感器的基本条件。在水性介质存在下，一些有机导电聚合物几乎立即变质。但是，聚（3,4-乙撑二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT：PSS）已证明在空气和水性介质中均具有稳定性。但是，由于PEDOT：PSS的结构和化学性质不足，它仍然存在主要障碍并阻碍了其在实际应用中的性能。通过碳纳米材料的组合可以克服这些缺点。因此，本研究研究了在PEDOT：PSS中加入还原氧化石墨烯（rGO）的效果，并增强了PEDOT：PSS / rGO纳米复合材料的结构，形态和电学性能。用PEDOT：PSS / rGO纳米复合材料制造了有机场效应晶体管（OFET），以检测重金属离子。这使得用于检测汞的高灵敏度和选择性传感器平台成为可能线性浓度范围1–60 nM中为²⁺。提出的OFET传感器具有对Hg ^2+的高灵敏度和选择性，低检测限为2.4 nM。测试了多种金属离子，即Hg 2 ⁺，Cd 2 ⁺，Pb 2 ⁺，Cu 2 ⁺，Zn 2 ⁺，Na ⁺和Fe ³⁺，以研究选择性。该传感器在水性介质中表现出稳定的性能，可在去离子水存在下检测Hg ²⁺。此外，在孵育Hg ²⁺离子溶液后的2到3 s内，OFET传感器做出了响应。