Organic electrochemical transistors (OECTs) have recently attracted attention due to their high transconductance and low operating voltage, which makes them ideal for a wide range of biosensing applications. Poly-3,4-ethylenedioxythiophene:poly-4-styrenesulfonate (PEDOT:PSS) is a typical material used as the active channel layer in OECTs. Pristine PEDOT:PSS has poor electrical conductivity, and additives are typically introduced to improve its conductivity and OECT performance. However, these additives are mostly either toxic or not proven to be biocompatible. Herein, a biocompatible ionic liquid [MTEOA]­[MeOSO3] is demonstrated to be an effective additive to enhance the performance of PEDOT:PSS-based OECTs. The influence of [MTEOA]­[MeOSO3] on the conductivity, morphology, and redox process of PEDOT:PSS is investigated. The PEDOT:PSS/[MTEOA]­[MeOSO3]-based OECT exhibits high transconductance (22.3 ± 4.5 mS μm–1), high μC* (the product of mobility μ and volumetric capacitance C*) (283.80 ± 29.66 F cm–1 V–1 s–1), fast response time (∼40.57 μs), and excellent switching cyclical stability. Next, the integration of sodium (Na+) and potassium (K+) ion-selective membranes with the OECTs is demonstrated, enabling selective ion detection in the physiological range. In addition, flexible OECTs are designed for electrocardiography (ECG) signal acquisition. These OECTs have shown robust performance against physical deformation and successfully recorded high-quality ECG signals.

The prevalence of microplastics (MPs) contamination in a broad spectrum of potable water sources has raised significant environmental and public health concerns. While evidence of ingested MPs bioaccumulation in the gastrointestinal tract (GIT) of aquatic and terrestrial organisms is mounting, the understanding of the effects of MPs on human gastrointestinal health remains scant. Herein, the potential deleterious biological effects of pristine and in vitro digested polystyrene (PS) MPs of varying sizes (i.e., 0.1, 1, and 10 µm) are systematically examined over a wide concentration range of 25–400 µg mL−1 on two human intestinal cell lines, namely Caco‐2 and NCM 460. Specifically, significant internalization of 0.1 and 1 µm PS ‐MPs have been observed in both cell types 24 h postexposure. However, multiparametric dose and time‐dependent analysis encompassing cell viability, reactive oxygen species (ROS), and nutrient absorption/metabolism measurement revealed no significant adversarial outcomes. Interestingly, it is found that the 0.1 µm PS‐MPs can perturb redox homeostasis in NCM460 but not in Caco‐2 cells. Based on the in vitro experimental boundaries and findings, it is concluded that ingested PS‐MPs pose little acute cytotoxic harm to human gastrointestinal health.

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