Needle-shaped potassium ion sensor and preparation method thereof

The invention discloses a needle-shaped potassium ion sensor and a preparation method thereof. The needle-shaped potassium ion sensor comprises a potassium ion selective electrode and a reference electrode, wherein the potassium ion selective electrode comprises a first metal wire; one end of the first metal wire serves as a first output end; the surface at the other end of the first metal wire is coated with a first solid-state electrolyte layer and a potassium ion sensitive film in sequence to form a first detection end; the reference electrode comprises a second metal wire; the surface at the other end of the second metal wire is coated with a second solid-state electrolyte layer and a reference film in sequence to form a second detection end; the first metal wire and the second metal wire are 0.1 to 0.6 mm in diameter, and 4 to 5 cm in length. As the potassium ion selective electrode and the reference electrode are made into needle-shaped and integrated, the needle-shaped potassium ion sensor can be used for detecting microbes, micro-blood and the like fast, and is convenient to carry, and simple and convenient to operate.