A method for analyzing concentration of an analyte in a liquid sample applied to a biosensor includes: applying a voltage pulse to the liquid sample applied to the biosensor, the voltage pulse having a pulse width of not greater than 10−3 second; monitoring a response current, which is produced in response to the voltage pulse, within the pulse width via electrodes of the biosensor; and analyzing the response current that is correlated to the concentration of the analyte in the liquid sample.