A system for detecting the presence of a target material, comprising: - a substrate capable of reversibly capturing fragrant molecules associated with the target material, and - a portable air sampling apparatus, including: - a Venturi pump, which comprises both an air flow channel, connecting a supply mouth and a discharge mouth of the Venturi pump, and a suction inlet emerging in the flow channel between the supply and discharge mouths, the Venturi pump being suitable for creating a vacuum in the suction inlet when the compressed air flows in the flow channel from the supply mouth to the discharge mouth, - a supply line provided to supply the Venturi pump with compressed air, the supply line being connected to the supply mouth and being provided with a solenoid valve, the opening and closing of which is electrically controlled and which controls the flow of compressed air in the supply line, - a suction line provided to suction an air sample, the suction line being connected to the suction inlet and being provided with an air circulation member, this air circulation member delimiting a receiving chamber for removably receiving the substrate and this air circulation member being suitable for circulating the suctioned air sample through the substrate received in the chamber, and - an electronic unit, connected to the solenoid valve and suitable for controlling the opening and closing of the solenoid valve such that: - when the solenoid valve is open, compressed air flows in the supply line through the solenoid valve, and - when the solenoid valve is closed, the flow of compressed air in the supply line, between the upstream and downstream directions of the solenoid valve, is interrupted by the solenoid valve. - a substrate capable of reversibly capturing fragrant molecules associated with the target material, and - a portable air sampling apparatus, including: - a Venturi pump, which comprises both an air flow channel, connecting a supply mouth and a discharge mouth of the Venturi pump, and a suction inlet emerging in the flow channel between the supply and discharge mouths, the Venturi pump being suitable for creating a vacuum in the suction inlet when the compressed air flows in the flow channel from the supply mouth to the discharge mouth, - a supply line provided to supply the Venturi pump with compressed air, the supply line being connected to the supply mouth and being provided with a solenoid valve, the opening and closing of which is electrically controlled and which controls the flow of compressed air in the supply line, - a suction line provided to suction an air sample, the suction line being connected to the suction inlet and being provided with an air circulation member, this air circulation member delimiting a receiving chamber for removably receiving the substrate and this air circulation member being suitable for circulating the suctioned air sample through the substrate received in the chamber, and - an electronic unit, connected to the solenoid valve and suitable for controlling the opening and closing of the solenoid valve such that: - when the solenoid valve is open, compressed air flows in the supply line through the solenoid valve, and - when the solenoid valve is closed, the flow of compressed air in the supply line, between the upstream and downstream directions of the solenoid valve, is interrupted by the solenoid valve. - a Venturi pump, which comprises both an air flow channel, connecting a supply mouth and a discharge mouth of the Venturi pump, and a suction inlet emerging in the flow channel between the supply and discharge mouths, the Venturi pump being suitable for creating a vacuum in the suction inlet when the compressed air flows in the flow channel from the supply mouth to the discharge mouth, - a supply line provided to supply the Venturi pump with compressed air, the supply line being connected to the supply mouth and being provided with a solenoid valve, the opening and closing of which is electrically controlled and which controls the flow of compressed air in the supply line, - a suction line provided to suction an air sample, the suction line being connected to the suction inlet and being provided with an air circulation member, this air circulation member delimiting a receiving chamber for removably receiving the substrate and this air circulation member being suitable for circulating the suctioned air sample through the substrate received in the chamber, and - an electronic unit, connected to the solenoid valve and suitable for controlling the opening and closing of the solenoid valve such that: - when the solenoid valve is open, compressed air flows in the supply line through the solenoid valve, and - when the solenoid valve is closed, the flow of compressed air in the supply line, between the upstream and downstream directions of the solenoid valve, is interrupted by the solenoid valve. - when the solenoid valve is open, compressed air flows in the supply line through the solenoid valve, and - when the solenoid valve is closed, the flow of compressed air in the supply line, between the upstream and downstream directions of the solenoid valve, is interrupted by the solenoid valve.