Deposition of ZnO-Valinomycin Film on Al Substrate for the Detection of K⁺ in KOH Solution

Chemically synthesized Nanocrystalline ZnO with valinomycin was deposited on Al substrate by modified chemically wet and dry (CWD) method. The lattice parameters a and c of ZnO are estimated to be 3.258 Å and 5.183 Å with an average crystallite size of 60 nm. The micrograph and energy dispersive X-ray spectrum analysis clearly indicates that ZnO is embedded in the valinomycin fibres. The ohmic character and non-magnetic character of the films is confirmed from the electrical and frequency dependent inductance characterisation. It is found that at higher frequency, impedance of the film does not depend upon the resistance and inductance. Hence the capacitance behaviour of the film is improved. The potassium sensing ability of the ZnO embedded valinomycin has a life time of 20 days which predicts that this organic polymer embedded ZnO can be used as a K⁺ detect biosensor.