In a recent study, a research team reported the design and development of a novel chemiresistor (CR) sensor for the detection of cadmium ions (Cd(II)) in water. The team used ion imprinted polymer (IIP)-functionalized reduced graphene oxide (rGO) to develop the IIP/rGO-CR sensor. The CR transducer of the sensor was made of rGO channel bridging source and drain electrodes. The researchers prepared the electrodes by selfassembly and thermal reduction of graphene oxide (GO) on Au interdigitated electrodes chip fabricated on Si/SiO2 substrate. After that, they grafted the IIP on rGO using surfaceinitiated reversible addition-fragmentation chain transfer (RAFT) polymerization. The IIP was developed using polyethylenimine (PEI) and methylacrylic acid (MAA) as dual functional monomers, and Cd(II) ions as a template through UV light-initiated copolymerization. This IIP functionalized on rGO acted as an effective recognition element that modulated the resistance of rGO-CR upon binding of Cd(II), enabling Cd(II) detection at ppb level in aqueous solutions. The team demonstrated that the prepared IIP/rGO-CR sensor worked effectively in the linear range of 2～200 ppb and achieved a limit of detection (LOD) of 0.83 ppb, which is lower than the World Health Organization guidelines of 3 ppb for drinking water quality. The researchers further tested the selectivity of the developed sensor against a variety of trace and heavy metal ions found in water and observed good stability for up to 60 days when stored at room temperature for Cd(II) determination in water. Additionally, the sensor was successfully applied to analyzing Cd(II) spiked in tap, lake, and river waters with a 94.5%-113.5% recovery, demonstrating a high degree of accuracy even in complex water samples. The study provided evidence of the successful imprinting process, binding and washing of the analyte, and the selective binding interaction of Cd(II) with the IIP of Cd(II)-ion imprinted poly(PEI + MAA) on the surface of rGO, which caused a significant change in the resistance of the rGO-FET device, enabling the detection of Cd(II) at sub-ppb level. The researchers suggested that the CR sensor of IIP functionalized rGO provides a potential platform for sensitive, robust, and low-cost environmental analysis of Cd(II) in water. The simple structure of the chemiresistive sensor combined with IIP functionalization approach makes this sensor an ideal candidate for developing on-site, rapid, and low-cost monitoring tools in real-world applications.