Optofluidic Immunosensor Based on Resonant Wavelength Shift of a Hollow Core Fiber for Ultratrace Detection of Carcinogenic Benzo[a]pyrene

Polycyclic aromatic hydrocarbons (PAHs) are always regarded as contaminants originating from the incomplete combustion of organic compounds. Benzo[a]pyrene (B[a]P) can be adopted as a marker for the overall PAH mixture due to its ultratoxic property, which can cause cancer of the lungs, skin, and prostate. It is necessary to monitor the B[a]P contamination levels in a water environment. In this article, an in-line fiber optofluidic sensor for the detection of B[a]P in water by using an antiresonant reflecting optical waveguide is proposed and experimentally demonstrated. One air hole in the cladding of the hollow-core fiber was fabricated as an in-line fiber optofluidic combined with two inlet and outlet microchannels fabricated by using femtosecond laser micromachining. The B[a]P molecule can be detected through the antiresonant reflecting optical waveguide due to the immunoreaction between the antibody and the target B[a]P. The experimental results show that a sensitivity of up to 23 pm/pM is achieved. The proposed fiber sensor appears to have potential applications in research on environmental contamination, food safety, human health, etc.