A subject material in a fluid sample is detected using a resonating sensor immersible in the fluid sample. Binding kinetics of an interaction of an analyte material present in the fluid sample are measured with the resonating sensor, which has binding sites for the analyte material. Prior to exposing the resonating sensor to the fluid sample, operation of the resonating sensor is initiated, producing a sensor output signal representing a resonance characteristic of the resonating sensor. Optionally, a reference resonator that lacks binding sites for the analyte is used to produce a reference output signal. Introduction of a fluid sample to the resonating sensor is automatically detected based on a characteristic change in the sensor output signal or a reference output signal. In response to the detecting of the introduction of the fluid sample, automated measurement of the binding kinetics are measured.