A method of detecting a defect in a barrier film. The method includes: coating the barrier film with a solution having a plurality of probes, where each of the probes has a nanoparticle; forcing a probe of the plurality of probes to penetrate the defect by applying a field to the barrier film, where the field induces an attractive power to the nanoparticles of the probes; applying an optical excitation (OE) to the barrier film; and identifying the defect in the barrier film based on an optical signal emitted, in response to the OE, by the probe forced to penetrate the defect.