A method of detecting cancer cells is disclosed. The method comprises (a) contacting the cell which is suspicious of a cancerous or undifferentiated phenotype with 4-aminophenyl phosphate (p-APP) under conditions wherein alkaline phosphatase of the cell catalyzes a reaction of the cell with the p-APP, so as to generate a product capable of producing an electrical signal; and (b) measuring a level of the electrical signal, wherein a difference in a level of the electrical signal compared to a predetermined threshold is indicative of a cancer cell.