Interference Of Anions On Ionophore-based Potassium Ion Nanosensor

Potassium ion plays an important role in living body,leading to one of the heated topics on detection of potassium ions inevitably.Compared to other types of chemical sensors,the new chemical sensor,ionophore-based selective nanosensor,has a number of advantages such as small size,simple preparation,bulk production and non-invasion to sample.These advantages make enormous applications possible in bioanalysis,especially in real-time analysis,bioimaging,medical diagnostics and therapy.Ionophore-based selective optical sensor emerged from the field of ion-selective membrane and the edged technology is focusing on the nano size and the introduce of solvatochromic dyes,with substantial reports on mechanism of detection,theoretical model and applications issued.However,there are still some problems in practical applications of this kind of sensor.For example,excessive interference from known and unknown substance may makes the detection results unreliable in the detection of complex samples such as biological fluids.In this paper,based on the ionophore-based potassium ion nanosensor,the anion interference to this kind of sensor was well studied in practical application.More lipophilic anions?such as ClO₄^-,SCN^-and I^-?and more hydrophilic anions(such as SO₄^2-,F^-,NO₃^-,Br^-and Cl^-)were regarded as background in the detection to K⁺.The results showed that all anions did have an interference on the detection of potassium ion and the more lipophilic anions exhibited much severer interference than the more hydrophilic anions.The study of the Zeta potential on the surface of the sensor nanoparticles proved that the adsorption of anions at the sensing interface lead to this phenomenon of interference.In detail,the more lipophilic anions performed stronger adsorption and greater interference to the detection of potassium ion.A new theoretical model was also established under the influence of anions,which is based on the previous theoretical model,addition to the effect of adsorption.This model theoretically explained the principle of anion interference and matched well with the experimental data of potassium ion detection,which proved the fact that the adsorption of anions contributed to the anion interference.The establishment of this theoretical model can provide a guidance for the solutions of anion interference to ion-selective sensor and a foundation for the real-world application of ionophore-based optical nanosensor in biological analysis in future.