Fiber optic interferometric immunosensor based on polydimethilsiloxane (PDMS) and bioactive lipids

Abstract

We demonstrate a novel and simple means to fabricate optical fiber immunosensors based on Fabry-Perot (F-P) interferometers using polydimethylsiloxane (PDMS) as support for bioactive lipids. The sensors are fabricated following a straightforward dip-coating method producing PDMS end-capped devices. A biosensing platform is realized by subsequent functionalization of the PDMS cap with a previously characterized bioactive lipid antigen cocktail from Mycobacterium fortuitum, used as a surrogate source of antigens for tuberculosis diagnosis. After functionalization of the PDMS, the F-P sensors were immersed in different antibody-containing sera and the registered changes in their spectral features were associated to the interactions between the active lipids and the serum antibodies. Our results show that the proposed PDMS end-capped F-P immunosensors perform well differentiating antibody-containing sera. Furthermore, they offer attractive attributes such as label-free operation, real-time detection capabilities and they are also reusable. The proposed sensors, therefore, serve as an enabling optical immunosensing technique offering excellent potential for developing novel lipidomic analytical tools.

Immunosensing Based on Optical Fiber Technology: Recent Advances

“…However, regenerating an immunosensor relies on detaching antigens from the antibodies on the fiber surface, a process that can damage the antibodies and hinder repeated usage. Therefore, while there is already some research regarding sensor regeneration and reusability using acid solutions [ 13 , 127 , 144 , 145 ], these remain a challenge for the future. In addition, the ability for detection of various parameters within a single optical fiber device [ 85 , 146 ] is another challenge to overcome in the promising future of biosensing.…”

Label-Free Optical Resonator-Based Biosensors

“…An optical fiber was originally developed to guide light waves along the core, which is surrounded by a cladding layer through the total internal reflection at the interface with negligible loss. Over the last few decades, optical fibers have been extensively investigated for biosensing applications, with the intrinsic advantages including flexibility, low-cost, small size, and biocompatibility [ 39 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 ]. To be developed as a biosensor, the structure of optical fiber has modified to maximize the interaction of light with target analytes and increase the sensitivity [ 66 ].…”

“…They were able to detect DTT down to 50 μM. Cano-Velazquez et al also reported a polydimethylsiloxane (PDMS)-coated optical fiber FPI as shown in Figure 11 b [ 72 ]. The PDMS has been widely used to fabricate optical and microfluidic devices by virtue of the transparency, ease-of-use, and biocompatibility.…”

Optical Technologies for Improving Healthcare in Low-Resource Settings: introduction to the feature issue

“…They demonstrate a fluorometric optical sensor system for the sensitive, real time measurement of volatile organic compounds (VOCs) as biomarkers of urinary bladder cancer. In Cano-Velázquez et al [15], functionalized polydimethylsiloxane enables label-free, real-time immunosensing of antigens for tuberculosis diagnosis. This work speaks to the more general promise of simple optical methods to enable novel analytical tools.…”