UV sensor for counterfeit currency notes detection

I want to find a sensor which has the capability of detecting a greenish fluorescent UV patch on a currency note when it is kept under a UV light. I have tried with many general purpose UV sensors, however it was not successful. Can you please tell me a UV sensor which has the capability of detecting the above mentioned UV patch ?

Following is the image of the currency note under a UV light.

i dont know about uv sensors, but i have got an idea, may be stupid but here goes..
try using a green filter and a regular light sensor like a photo diode.

Thanks a lot for your quick reply. That is one of the alternatives I have considered. I will check the possibility that solution.

Not stupid, just a matter of reasoning. By nature of fluoresence, it has to be measured at the emitted wavelength (green) rather than the excitation wavelength (UV).

The fluorescense intensity is however low and the safety feature is the specfic pattern, not a some glow of green light.