An array type of sensor displaying independent specificity for multiple targets can be an attractive platform. Fourth, portability and ease-of-use are important for on-site monitoring. In addition, automation can be a significant factor of consideration for a long-term environmental monitoring.The function of a pathogenic biosensor is to transduce receptor recognition towards the target pathogen into a detectable signal. Pathogenic sensing relies on either immunosensing or nucleic acid detection. Immunosensors are based on the interaction between antigens presented on the target cells and antibodies immobilized on surfaces. The resulting conjugates have been detected via various sensing methods, including fluorescence [5], electrical or electrochemical impedance [5,6], cantilever [7,8], quartz crystalline microbalance (QCM) [2,7], surface plasmon resonance (SPR) [5,7], and magnetoresistivity [9].

Nucleic acid-based sensors detect DNA or RNA originating from target cells. Because cells contain a low copy number of nucleic acids, the sensor generally requires a step of amplifying target nucleic acids using polymerase chain reaction (PCR) or reverse transcriptase PCR (RT-PCR). In addition, there are several intricate strategies for amplifying signals that report the hybridization between probe and target DNA. Using nanoparticles [10] and enzyme labels [11], redox probes [12-14], and intercalators [15] are among those strategies. The target DNA or RNA will also be detected using various physical sensing methods.

In general, the ultimate performance of a pathogen sensor relies on the high efficiency of biochemical reactions, high concentration of target analytes, and sensitive detection or transduction methods.Recent advances in micro- and nano-fabrication technologies have provided unique advantages for developing pathogen sensors in several respects. The sensor probe created with similar or smaller dimensions of a bacterial cell could provide high sensitivity and a low detection limit. Nanoparticles, nanotubes, nanowires, and nanomechanical devices are representative examples used as functional probes for detecting Batimastat pathogens. In addition, microfabrication technology has made it possible to integrate multiple processes in sequence for one-step sensing or in parallel for high throughput screening.

In this review, we will highlight a group of pathogen sensors developed in the last several years that have taken advantage of advanced micro- and nano-technology. This paper will focus on the principles, features, and advantages of new sensing technologies. We will also describe how the technology could enhance the sensor sensitivity and detection limit.2.?Recent Sensing Strategies for Pathogen Detection Based on MicrofluidicsOne of the main outcomes of microfabrication technology is the creation of microfluidic devices, so called labs-on-a-chip.