Sensor

A sampling apparatus comprising a housing coupled to a sampling port and incorporating a sensor and a signal processing unit in electronic communication with the sensor, wherein the sensor comprises:

• a substrate;
• a channel disposed on the substrate;
• at least one transducer disposed in the channel;
• and
• a filter for selectively absorbing the analyte in preference to the at least one interferent, wherein the filter is arranged in the channel remotely from the at least one transducer and wherein the channel defines a flow path for the fluid sample such that the fluid sample contacts a first transducer to generate a first signal, followed by the filter, followed by the first transducer or a second transducer to generate a second signal.

A method of detecting an analyte in the presence of at least one interferent in a fluid sample comprising providing a fluid sample potentially containing the analyte, contacting the fluid sample with a sensor so as to obtain a first and second signals, and comparing the first and second signals to provide an indication of the amount of the analyte present in the sample, wherein the sensor comprises:

• a substrate;
• a channel disposed on the substrate;
• at least one transducer disposed in the channel;
• and
• a filter for selectively absorbing the analyte in preference to the at least one interferent, wherein the filter is arranged in the channel remotely from the at least one transducer and wherein the channel defines a flow path for the fluid sample such that the fluid sample contacts a first transducer to generate the first signal, followed by the filter, followed by the first transducer or a second transducer to generate the second signal.