Fluorescence sensor and method for producing thin metal film with apertures to be used by the fluorescence sensor

A fluorescence sensor, comprising

• a light source, for emitting an excitation light beam;
• a substrate formed of a material that transmits the excitation light beam, provided at a position that receives the excitation light beam;
• a detection section that includes a finely apertured thin metal film, formed on a surface of substrate other than the surface onto which the excitation light beam is incident;
• a sample supplying section, for supplying samples containing fluorescent labels and detection target substances such that the samples contact the detection section;
• and
• a photodetector for detecting fluorescence from the fluorescent labels;
• the fluorescence sensor being configured such that the excitation light beam enters the interface between the substrate and the finely apertured thin metal film of the detection section;
• the fluorescent labels are excited by at least one of:
• near field light generated at the fine apertures of the finely apertured thin metal film and surface plasmon on the finely apertured thin metal film induced by the near field light;
• and
• the fluorescence emitted from the fluorescent labels is detected by the photodetector.