Trace detection of canine distemper virus based on surface-functionalized optic-fiber Mach–Zehnder interferometer and the Vernier effect

Abstract A surface-functionalized cascaded optic-fiber Mach–Zehnder interferometer (MZI) is proposed and fabricated for trace detection of canine distemper virus (CDV). The Vernier effect is formed based on single-mode fiber (SMF)-dislocation single-mode fiber-SMF. The two MZIs serve as the sensing arm and reference arm, respectively. The CDV antibody is modified on the sensing arm to detect CDV antigen, and the surface structure and morphology are analyzed by the atomic force microscope. The sensitivity of the cascaded MZI sensor is about 12 times than that of a single MZI. In the range of 0.1–10 4 pg ml −1 CDV, the detection limit of the cascaded MZI sensor is 0.1687 pg ml −1 , and the response time is 25 min. The sensor also has good temperature, time stability and excellent selectivity. The biosensor has the advantages of low cost, easy preparation, high sensitivity and good selectivity, and has potential application for trace CDV detection.