Abstract: A test strip includes a working electrode including a conductive layer and an electro-catalytic layer deposited on the conductive layer. A method for simultaneously detecting a glucose concentration and a percentage of glycated hemoglobin in a single test strip includes following steps: providing a blood sample, providing the aforementioned test strip, performing a sample injecting step, performing an initial step, performing a first detecting step, performing a second detecting step, performing a third detecting step, performing a first analyzing step, and performing a second analysis step.