A solid-core photonic crystal fiber (SC-PCF) with a microstructured all-silica steering wheel lattice containing a 3 μm diameter core is used to identify dye-free enzyme-linked monoclonal antibodies (mAbs) of very small volumes <0.1uL for concentrations ranging from 0.1mg/mL to 10^-12 mg/mL. The samples used in this study are mAbs, which are useful in detecting the presence of the botulism toxin. Human IgG antibodies (Southern Biotech Inc.) served as the “coating” antibody to detect an enzyme-linked mAb (Southern Biotech Inc.) - the “antigen”. The spectra for mAb samples linked with enzymes were compared to control samples without enzymes and conventional ELISA measurements. The SC-PCF at lengths 1m and 0.5m were filled with ~ 0.008 μL of each sample was coupled with a broadband LED light source with emission peaks in the 1280-1700 nm range. Absorption characteristics associated with these mAbs were measured using a standard optical spectrum analyzer. Spectra were collected for control antibody samples, enzyme-linked antibody and a third sample of a mixture of both antibodies. The measured spectra for the samples with varied concentrations were consistent with conventional ELISA measurements. Limitations due to bend loss were also investigated. A compact, real-time sensor based on this dye-free technology has the potential to benefit water quality monitoring, drug manufacturing and food quality control.

Date Published: 23 April 2013
PDF: 8 pages
Proc. SPIE 8693, Smart Sensor Phenomena, Technology, Networks, and Systems Integration 2013, 86930U (23 April 2013); doi: 10.1117/12.2009509

Published in SPIE Proceedings Vol. 8693:
Smart Sensor Phenomena, Technology, Networks, and Systems Integration 2013
Kara J. Peters; Wolfgang Ecke; Theodoros E. Matikas, Editor(s)