Real-Time Two-Dimensional Imaging of Potassium Ion Distribution Using an Ion Semiconductor Sensor with Charged Coupled Device Technology

摘要

Two-dimensional real-time observation of potassium ion distributions was achieved using an ion imaging device based on charge-coupled device (CCD) and metal-oxide semiconductor technologies, and an ion selective membrane. The CCD potassium ion image sensor was equipped with an array of 32 × 32 pixels (1024 pixels). It could record five frames per second with an area of 4.16 × 4.16 mm~(2). Potassium ion images were produced instantly. The leaching of potassium ion from a 3.3 M KCl Ag/AgCl reference electrode was dynamically monitored in aqueous solution. The potassium ion selective membrane on the semiconductor consisted of plasticized poly(vinyl chloride) (PVC) with bis(benzo-15-crown-5). The addition of a polyhedral oligomeric silsesquioxane to the plasticized PVC membrane greatly improved adhesion of the membrane onto Si_(3)N_(4) of the semiconductor surface, and the potential response was stabilized. The potential response was linear from 10~(?2) to 10~(?5) M logarithmic concentration of potassium ion. The selectivity coefficients were K _(K~(+),Li~(+))~(pot) = 10~(?2.85), K _(K~(+),Na~(+))~(pot) = 10~(?2.30), K _(K~(+),Rb~(+))~(pot) =10~(?1.16), and K _(K~(+),Cs~(+))~(pot) = 10~(?2.05).