A sensor for determining the concentration of a component of a fluid flow, the sensor comprising - a substrate , - at least one heater element arranged on the substrate , - at least one adsorbing layer selected to adsorb the component, - a control and energy supply element for regulating a pulsed supply of energy to the heater element , wherein the heater element is in thermal contact with the adsorbing layer such that a heat pulse during operation of the heater element increases the temperature of the adsorbing layer to a temperature level (T_high) equal or above a desorption temperature (T_desorp) of the component, characterized in that the sensor further comprises - at least one temperature sensor in thermal contact with the adsorbing layer for monitoring a temperature response of the adsorbing layer to the heat pulse by measuring a temperature curve, wherein the sensor is configured to convert the temperature curve of the adsorbing layer at or above the desorption temperature (T_desorp) into a parameter representative of the concentration of the component, wherein the sensor is configured to detect a carbon dioxide concentration and wherein the sensor is configured such that the desorption process at or above the desorption temperature (T_desorp) is an endothermal process such that energy is required to release the adsorbed component from the adsorbing layer . - a substrate , - at least one heater element arranged on the substrate , - at least one adsorbing layer selected to adsorb the component, - a control and energy supply element for regulating a pulsed supply of energy to the heater element , wherein the heater element is in thermal contact with the adsorbing layer such that a heat pulse during operation of the heater element increases the temperature of the adsorbing layer to a temperature level (T_high) equal or above a desorption temperature (T_desorp) of the component, characterized in that the sensor further comprises - at least one temperature sensor in thermal contact with the adsorbing layer for monitoring a temperature response of the adsorbing layer to the heat pulse by measuring a temperature curve, wherein the sensor is configured to convert the temperature curve of the adsorbing layer at or above the desorption temperature (T_desorp) into a parameter representative of the concentration of the component, wherein the sensor is configured to detect a carbon dioxide concentration and wherein the sensor is configured such that the desorption process at or above the desorption temperature (T_desorp) is an endothermal process such that energy is required to release the adsorbed component from the adsorbing layer . wherein the sensor is configured to convert the temperature curve of the adsorbing layer at or above the desorption temperature (T_desorp) into a parameter representative of the concentration of the component, wherein the sensor is configured to detect a carbon dioxide concentration and wherein the sensor is configured such that the desorption process at or above the desorption temperature (T_desorp) is an endothermal process such that energy is required to release the adsorbed component from the adsorbing layer . <EOS>