Warm temperature thermal stimulation enhanced X-ray induced narrow-band UVB afterglow as long time safe irradiation source for phototherapy of psoriasis

A NB-UVB long persistent luminescence phosphor Ca 2 GeO 4 : Gd 3+ was synthesized, and the remaining luminescence decay lasted for more than 12 h. • After heating treatment, the NB-UVB afterglow intensity of the flexible film increased by three times. • The heat generated by short-term sunlight exposure can also enhance the emission of NB-UVB afterglow. Narrow-band UVB (NB-UVB) is markedly efficacious option for the treatment of psoriasis. However, the NB-UVB therapy still requires specialized medical equipment to avoid the possible risk of skin injury, which has poor portability and then limits its further application. Here, we have prepared a flexible film containing long afterglow NB-UVB phosphor Ca 2 GeO 4 : Gd 3+ , which persistent NB-UVB afterglow emission at 314 nm can be regarded as long time safe irradiation source for the phototherapy of psoriasis. Our results have shown that CGO: Gd 3+ can continuously release NB-UVB photons for more than 12 h, indicating that long time mild UVB irradiation source can be realized. More importantly, after warm temperature treatment, the NB-UVB afterglow emissions of the flexible film are enhanced to 3 times stronger, indicative of the recovery of high phototherapy efficiency. Furthermore, short-time sunlight induced heat also can enhance the NB-UVB afterglow emission intensity obviously, indicating high phototherapy efficiency can be kept when the film is exposed to sunlight. This work provides a low-cost UVB phototherapy method with multiple thermal stimuli to enhance afterglow, which has great potential in the home treatment of psoriasis. Ca 2 GeO 4 : Gd 3+ film can continuously emit NB-UVB afterglow for more than 12 h, which can be considered as a long-term safe and portable irradiation source for psoriasis phototherapy. And after heat treatment, the NB-UVB afterglow emission of the flexible film was enhanced by three times. More importantly, short-term sunlight induced heat can significantly enhance the afterglow emission intensity of NB-UVB, indicating that the film can maintain high phototherapy efficiency when exposed to sunlight. Download: Download high-res image (149KB) Download: Download full-size image