Patent ID: 8180421

Claim:
A method for detecting the presence or amount of a pathogen that is a source of a hospital acquired infection comprising: locating an optical fiber in an environment, the optical fiber having directly or indirectly attached thereto a first group of molecules at a site that is within the evanescent field of the core of the optical fiber, the first group of molecules including an acceptor molecule, one of the molecules of the group being attached to the optical fiber with a first tether, the first tether comprising a substrate cleavable by an enzyme that is expressed by the pathogen; retaining the optical fiber in the environment such that enzyme present in the environment will cleave the substrate; transmitting an excitation signal to the site via the optical fiber, the excitation signal comprising an excitation wavelength specific for a donor molecule; transmitting an optically detectable emission signal from the site following any cleaving of the substrate by action of the enzyme; and determining the presence or amount of the pathogen in the environment based on the detectable emission signal.