An ENG-Inspired Microwave Sensor and Functional Technique for Label-Free Detection of Aspergillus Niger

Aspergillus Niger is an airborne fungal pathogen which commonly affects the vegetation. More importantly, the toxins carried by its micrometer-sized spores can be easily inhaled through surrounding atmosphere and causes respiratory diseases in human. Thus, their detection in the surrounding media is important. In this paper, a microwave sensor based on epsilon negative structure is realized. The sensor has two complementary ring resonators in the horn-shape and U-shape. A label-free detection approach is presented in which a functionalized glass slide attached with fungi specific enzyme is mounted on the sensor. The air fringing fields of the complementary rings interact with the fungi immobilized glass slide to produce a change in the resonant frequency. A prototype sensor system is also proposed for low-cost measurement of sensor frequency response into equivalent DC signaling. The proposed sensor is suitable for real-time monitoring of fungal contamination of air in the industrial processes.