Fabrication and characterization of a fiber optic surface plasmon resonance (SPR) based potassium ion (K⁺) sensor utilizing the coating of dicyclohexeno-18-crown-6 ionophore incorporated in plasticized PVC membrane along with lipophilic pH sensitive dye chromoionophore-I over the silver coated unclad core of the fiber have been carried out. The interaction between ion selective cocktail layer and incoming K⁺ changes the effective refractive index of the sensing layer which affects the resonance wavelength in the SPR spectrum. To achieve best sensor performance, the thickness of the sensing layer has been optimized. The sensor probe has been found to be irreversible due to the very strong interaction between ionophore and target K⁺. The ring type structure of ionophore used provides a close fit to the incoming K⁺ and hence interacts strongly with it which makes K⁺ incapable of leaving the cavity of the ionophore. The washing of sensor probe with DI water could not break this bonding. This results in one time use of the probe or disposable type sensor probe. However, the probe works for 0 to 180 µg/mL concentration range of K⁺. The sensor is highly selective to K⁺ and is not affected by nitrate, phosphate, calcium and sodium ions and can be used to check the concentration of K⁺ in soil. In addition, the sensor possesses a response time of around 50 sec. Since the probe has been fabricated on optical fiber it has various advantages such as miniaturization, low cost, fast response, capability of real time monitoring and remote sensing.

利用掺入增塑PVC膜中的dicyclohexeno-18-crown-6离子载体和亲脂性pH敏感染料chromoionophore-I，在光纤表面等离振子共振（SPR）基钾离子（K ⁺）传感器上进行制备和表征已经对纤维进行了包覆的未包层纤芯。离子选择性混合物层与入射K ⁺之间的相互作用会改变传感层的有效折射率，从而影响SPR光谱中的共振波长。为了获得最佳的传感器性能，已优化了感应层的厚度。由于离子载体与靶K ⁺之间非常强的相互作用，已发现传感器探针不可逆。。所使用的离子载体的环状结构提供了与传入的K ⁺的紧密配合，因此与之紧密相互作用，这使得K ⁺无法离开离子载体的腔。用去离子水清洗传感器探头不会破坏这种结合。这导致一次使用探头或一次性传感器探头。但是，该探针可在0至180 µg / mL的K ⁺浓度范围内工作。该传感器对K ⁺具有很高的选择性，不受硝酸盐，磷酸盐，钙和钠离子的影响，可用于检查K ⁺的浓度在土壤中。另外，传感器具有约50秒的响应时间。由于探头是在光纤上制造的，因此具有各种优点，例如小型化，低成本，快速响应，实时监控和遥感功能。