A heat dissipation device used for dissipating heat from an electronic device mounted on a printed circuit board, includes a heat sink contacting with the electronic device, a locking device mounted on the heat sink and securing the heat sink onto the PCB. The method for detecting an explosive of the present invention makes an explosive come in contact with a quantum dot thin film to which an explosive can combine, and measures a change in fluorescence wavelength, thereby sensing an explosive. The reagent containers are adapted for cooperation with the probe tip.