Label-free ferrule-top optical fiber micro-cantilever biosensor

Micro-cantilever sensors have shown great promise in a wide range of applications including chemical medical and biological sensing. However, many of these devices are based upon a sensor ‘chip’ that requires careful alignment between the cantilever and the read-out system, which can be challenging. Furthermore, optical interrogation typically involves a bulky free-space system. Optical fiber addressed cantilevers have been reported previously in the literature and in this paper we propose techniques to design and fabricate polymer micro-cantilevers onto the end of standard single mode fibers using ns-laser machining. The cantilever will deflect and thereby observing biological binding between species of interests and activated cantilevers. Proof-of-concept experiments demonstrate that the sensor is capable of detecting Listeria food pathogen concentrations with a minimum level of less than 10⁵cfu/ml.