Bacteria sensor and method
Bacteria accumulations on the interior walls of a fluid conduit are detected by placing a bacterial target substrate in the conduit. The substrate is structured to allow bacteria to colonize it at at least the rate of accumulation expected on the conduit walls or at an accelerated rate in order to preempt normal bacteria accumulation on the walls. A bacteria getter may be used to accelerate bacterial colonization of the substrate. An excitation signal interrogating the substrate causes autofluorescence in the presence of bacteria, specifically from NADH and/or NADPH present. The autofluorescent emission is transmitted to a detector and processor. In one system when the presence of bacteria at a preset level is detected there is initiated a diversion of the fluid into an auxiliary subsystem during which the primary subsystem is remediated. In one configuration, a wall portion is transparent and the biofilm target substrate is integral with the transparent wall portion and the sensor head is attached to the outside of the transparent wall portion. It can be made as a removable and/or disposable cell in which the transparent wall portion is a glass plug that fits into a hole in the conduit. The biofilm target substrate can be a getter affinity surface formed on the inside surface of the glass plug. Various means are used for obtaining accelerated biofilm growth.
1. Apparatus for detecting biofilm in a fluid system comprising;
a wall portion having an outside surface outside the fluid flow and an inside surface in contact with the fluid flow and being transparent to excitation and emitted light;
a biofilm target substrate integral with the inside surface in contact with fluid in the fluid system;
an optical fiber sensor in optical contact with the outside surface and having at least one fiber (excitation fiber) for sending excitation light through the wall portion to the biofilm substrate and at least one fiber for receiving emitted autofluorescence from the biofilm caused by the excitation light (emission fiber).
2. The apparatus of claim 1 wherein the biofilm target substrate is a getter affinity substrate.
3. The apparatus of claim 2 wherein the getter affinity substrate has cavities for promoting the growth of bacteria in the cavities.
4. The apparatus of claim 2 wherein the getter affinity substrate has sticky glycosides for promoting the growth of bacteria.
5. Apparatus for detecting biofilm in fluid systems comprising;
a detection cell having a transparent wall portion and being configured to fit in an aperture in a fluid carrying conduit the transparent wall portion having an outside surface and an inside surface;
a biofilm target substrate on the inside surface enabled to allow the growth of biofilm;
a receptacle for attaching a fiber optic sensor head in optical communication through the wall portion to the surface portion on the inside surface.
6. The detection cell of claim 5 further wherein the biofilm target substrate on the inside surface is a getter affinity substrate.
7. The apparatus of claim 6 wherein the getter affinity substrate has cavities for promoting the growth of bacteria in the cavities.
8. The apparatus of claim 6 wherein the getter affinity substrate has sticky glycosides for promoting the growth of bacteria.